JP2004106537A - Manufacturing method for polyester film coated metal sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method for a polyester film coated metal sheet excellent in economical efficiency and can fabricating properties and having good heat resistance even in an outer surface baking and coating process performed for the purpose of obtaining a beautiful appearance after can fabrication. <P>SOLUTION: After a molten resin film, which is obtained in the confluent state with an olefinic polymer using a T-die, is cooled and solidified, both end parts of the film are cut off to obtain a polyester film. The polyester film is constituted of an A-layer, a B-layer and a C-layer. The A-layer comprises a polyester with a crystallization temperature upon falling temperature of 150°C or higher, the B-layer comprises a polymer which consists of a polyester and an olefinic polymer in a weight ratio of 70:30-100:0 and has a melting point of 190-225°C and a glass transition temperature of 50°C or higher and the C-layer comprises a polyester with a glass transition temperature of 30-50°C. <P>COPYRIGHT: (C)2004,JPO

Description

The present invention relates to a method for producing a metal film coated with a polyester film. More specifically, the present invention relates to a method for producing a polyester-film-coated metal sheet having excellent can-making properties (for example, drawing and ironing workability).

Conventionally, the inner surface and outer surface of metal cans are coated with various thermosetting resins such as epoxy or phenol dissolved or dispersed in a solvent to prevent corrosion. Has been done. However, this method of coating with a thermosetting resin has disadvantages in that it often takes a long time to dry the paint, resulting in a decrease in productivity and undesired problems such as environmental pollution due to a large amount of organic solvents.
In order to solve such a defect, a method of coating a metal plate with a thermoplastic resin by a melt extrusion method has been disclosed (for example, see Patent Document 1). Further, a method is disclosed in which a melt-extruded thermoplastic resin is once cooled and solidified, and then pressure-bonded to a heated metal plate (for example, see Patent Document 2). Further, a method is disclosed in which a non-oriented film of polyethylene terephthalate and / or polybutylene terephthalate produced by a melt extrusion method is pressure-bonded to a heated metal plate (for example, see Patent Document 3).
JP-A-57-203545 JP-A-10-309775 JP 2001-1447 A

However, in these thermoplastic resin coating methods, when the molten resin is extruded in a layer form from a T-die, the width of the molten resin film greatly decreases (referred to as neck-in), and is several tens of cm with respect to the resin width required for coating. It was necessary to form a film with a wide width, and it was not a method that was satisfactory in terms of economy.
In order to solve such a drawback, a method of reducing neck-in by using a polyester obtained by blending a polyester obtained by copolymerizing a trifunctional or higher polybasic acid or a polyhydric alcohol component is disclosed (for example, Patent Documents 4 and 5).
JP-A-10-86308 JP-A-2000-71388

However, in these coating methods, a polyester obtained by copolymerizing a trifunctional or higher polybasic acid or a polyhydric alcohol component is liable to be thermally degraded in a melting step from an extruder to a T-die, and even when a heat stabilizer is used in combination. Foreign matter (for example, a gel-like foreign matter or a foreign matter having a degraded substance as a nucleus) is likely to be generated in the obtained molten resin film, and a crack originating from the foreign matter is formed in the resin coating layer at the time of can making. It was not satisfactory as a coated metal plate.
In addition, the resin used for coating the resin-coated metal sheet used for drawing and ironing cans must not only have excellent formability that can follow can making (drawing and ironing), but also beautify after can making. It is required that impact resistance does not decrease even when heating the external surface baking coating performed for the purpose. However, the impact resistance of the resin-coated metal sheet is often lowered, and the impact resistance is not satisfied.
Also, many methods of laminating a polyester film on a metal plate have been disclosed (for example, Patent Document 6, Patent Document 7, Patent Document 8).
JP-B-57-23584 JP-B-59-34580 JP-B-62-61427

However, in this technology, when laminated with a metal plate at a temperature equal to or higher than the melting point of the polyester constituting the film and brought into close contact with the metal plate, the impact at the time of the can-making process, that is, the impact at a high speed against the stopper hits the bottom of the can. Local film tearing (cracks) occurred, and a polyester film-coated metal plate satisfactory for can-making could not be obtained.
In order to improve the flexibility of the polyester-based film to secure the impact resistance in order to solve such a drawback, not only is it adhered to the processing punch in the can-making process, but also for the purpose of beautification after can-making. A problem caused by insufficient heat resistance that the transfer pins are likely to be traced during transfer in the heating process of the outer surface baking coating, etc., which is satisfactory as a polyester film coated metal plate for the purpose of protecting the inner layer of a metal can Was not.

The present invention aims to solve the above-mentioned problems of the prior art. In other words, the neck-in during melt extrusion is small, and foreign matters are hardly generated in the obtained molten resin film, and the impact resistance is good, so that it is excellent in economic efficiency and can making property, and beautiful after can making. An object of the present invention is to provide a method for producing a polyester film-coated metal sheet having good heat resistance even in the transfer of the outer surface baking coating step performed for the purpose.

An object of the present invention is to provide a manufacturing method for coating a metal plate with a polyester having a melting point of 180 ° C. or more by cooling and solidifying a molten resin film obtained in a state where olefin-based polymers are joined at both ends using a T-die. The obtained resin film is monoaxially stretched in the longitudinal direction, then heat-set, and then cut and removed at both ends to obtain a polyester film, and the polyester film is laminated on a metal plate heated in another step. A polyester-based film comprising a layer A, a layer B and a layer C, wherein the layer A comprises a polyester having a temperature-reducing crystallization temperature of 150 ° C. or higher; The layer is composed of a polyester and an olefin-based polymer having a melting point of 190 to 225 ° C. and a glass transition temperature of 50 ° C. or more, from 70:30 to 100: 0 (% by weight). And C, wherein the polyester layer has a glass transition temperature of 30 to 50 ° C., and the polyester film has a heat shrinkage in the longitudinal direction at 150 ° C. of 4 to 30%. This is achieved by a method for producing a system film-coated metal plate.

The method for producing a metal sheet coated with a polyester-based film of the present invention is not only an economical production method because it is possible to reduce waste of raw materials, but also has a can-making property (a releasing property of a processing punch, an adhesive property of a film, a resistance to film resistance). This is a method of producing a polyester film-coated metal sheet having excellent crack resistance and heat resistance. Furthermore, since the thermal characteristics of each layer are well-balanced and the film is less likely to wrinkle even in the heat treatment step after can-making, it can be said that this is a very useful method for producing a polyester film-coated metal sheet.

The polyester constituting the layer A of the polyester film in the present invention is required to have a temperature-reducing crystallization temperature of 150 ° C. or more from the viewpoint of securing heat resistance. If the cooling crystallization temperature is lower than 150 ° C., defects due to insufficient heat resistance, such as sticking of the punch and the film at the time of can-making and traces of transport pins remaining on the film in the heat treatment step, occur. The higher the cooling crystallization temperature, the more the heat resistance is improved. However, if the cooling crystallization temperature exceeds 200 ° C., the rigidity of the film increases, and the film cannot follow the deformation during the can-making process, and cracks are formed on the can wall. appear. Further, since the film-forming property of the film is remarkably reduced, the temperature-reducing crystallization temperature is preferably 200 ° C. or less. The polyester constituting the layer A may contain one kind of dicarboxylic acid component and / or glycol component, or may contain two or more kinds. For example, as a dicarboxylic acid component, aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, orthophthalic acid, naphthalenedicarboxylic acid, diphenylsulfonedicarboxylic acid, 5-sodium sulfoisophthalic acid, oxalic acid, succinic acid, adipic acid, sebacic acid, Aliphatic dicarboxylic acids such as decanedicarboxylic acid, maleic acid, fumaric acid, and dimer acid, oxycarboxylic acids such as p-oxybenzoic acid, and alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid can be used. Examples of the glycol component include aliphatic glycols such as ethylene glycol, propanediol, butanediol, pentanediol, hexanediol, and neopentyl glycol; alicyclic glycols such as cyclohexanedimethanol; and aromatic glycols such as bisphenol A and bisphenol S. Can be used.
The thickness of the layer A is preferably from 1 to 20 μm, more preferably from 2 to 15 μm. When the thickness is less than 1 μm, the effect of improving heat resistance is not sufficient, which is not preferable. Conversely, if it exceeds 20 μm, the effect of improving heat resistance is not only saturated, but also cracks are likely to occur during can making, which is not preferable.

It is necessary that the polyester constituting the layer B of the polyester film in the present invention has a melting point of 190 to 225 ° C and a glass transition point of 50 ° C or higher in order to secure impact resistance. If the melting point exceeds 225 ° C., cracks are likely to occur during can making, which is not preferable. When the melting point is less than 190 ° C. or the glass transition point is less than 50 ° C., cracks are less likely to occur during can making, but the balance of thermal properties with the layer A is poor, and the film is laminated with a metal plate or after can making. In the heat treatment step, wrinkles are easily formed in the film, which is not preferable. It is necessary that the polyester and the olefin-based polymer having a melting point of 190 to 225 ° C and a glass transition point of 50 ° C or more are 70:30 to 100: 0% by weight. If the amount of the olefin-based polymer exceeds 30% by weight, the heat resistance tends to decrease, which is not preferable.
The polyester constituting the layer B may contain one type of dicarboxylic acid component and / or glycol component, or two or more types. For example, as a dicarboxylic acid component, aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, orthophthalic acid, naphthalenedicarboxylic acid, diphenylsulfonedicarboxylic acid, 5-sodium sulfoisophthalic acid, oxalic acid, succinic acid, adipic acid, sebacic acid, Aliphatic dicarboxylic acids such as decanedicarboxylic acid, maleic acid, fumaric acid, and dimer acid, oxycarboxylic acids such as p-oxybenzoic acid, and alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid can be used. Examples of the glycol component include aliphatic glycols such as ethylene glycol, propanediol, butanediol, pentanediol, hexanediol, and neopentyl glycol; alicyclic glycols such as cyclohexanedimethanol; and aromatic glycols such as bisphenol A and bisphenol S. Can be used.

The olefin polymer blended with the polyester constituting the B layer is preferably polyethylene and / or an ethylene copolymer. Low density polyethylene, medium density polyethylene, high density polyethylene, linear low density polyethylene, ultra high molecular weight polyethylene, ethylene-propylene copolymer, ethylene-butene copolymer, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate Copolymer, ethylene-methyl acrylate copolymer, ethylene-methyl methacrylate copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene-ethyl acrylate-maleic anhydride copolymer, ionomer , An ethylene-maleic anhydride graft copolymer, an ethylene-vinyl alcohol copolymer, and the like. It is preferable that the olefin-based polymer used in both ends of the molten resin film and the B layer is the same. The reason is that the resin extruded in a layered form is cooled and solidified from the viewpoint of reducing waste of the resin, and then the resin obtained by cutting and removing both ends of the resin film obtained by longitudinally uniaxial stretching and heat-setting is coated with a B layer. This is because the quality of the polyester-based film coated on the metal plate becomes stable when reused.
The thickness of the layer B is preferably from 3 to 60 μm, more preferably from 5 to 40 μm. If it is less than 3 μm, cracks are likely to occur during can making, which is not preferable. Conversely, if it exceeds 60 μm, cracks are less likely to occur during can making, but heat resistance is lowered and the cost is disadvantageous, which is not preferable.
Further, it is preferable that both ends of the layered molten resin film extruded from the T die and the olefin polymer used in the B layer are the same. The reason is that when the resin containing both ends obtained by cutting and removing the resin extruded in layers after cooling and solidifying from the viewpoint of reducing waste of the resin is reused in the B layer, the resin film coated on the metal plate becomes This is because the quality is stable.
In the present invention, when the resin containing both ends is reused, the reuse ratio is not particularly limited, but is preferably 5 to 60 (% by weight).

The polyester constituting the layer C needs to have a glass transition temperature of 30 to 50 ° C. When the glass transition point of the polyester constituting the C layer exceeds 50 ° C., depending on the metal plate used (especially when tinplate is used), film peeling occurs on the can wall during can-making, and this peeled portion is used as a starting point. Undesirably, cracks easily occur. When the glass transition point is lower than 30 ° C., the balance between the thermal properties of the layer A and the layer B is deteriorated, and the film is easily wrinkled in the case of laminating the film with a metal plate or in the heat treatment step after can making. .
The polyester constituting the C layer may contain one type of dicarboxylic acid component and / or glycol component, or two or more types. For example, as a dicarboxylic acid component, aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, orthophthalic acid, naphthalenedicarboxylic acid, diphenylsulfonedicarboxylic acid, 5-sodium sulfoisophthalic acid, oxalic acid, succinic acid, adipic acid, sebacic acid, Aliphatic dicarboxylic acids such as decanedicarboxylic acid, maleic acid, fumaric acid, and dimer acid, oxycarboxylic acids such as p-oxybenzoic acid, and alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid can be used. Examples of the glycol component include aliphatic glycols such as ethylene glycol, propanediol, butanediol, pentanediol, hexanediol, and neopentyl glycol; alicyclic glycols such as cyclohexanedimethanol; and aromatic glycols such as bisphenol A and bisphenol S. Can be used.
The thickness of the C layer is preferably from 1 to 15 μm, more preferably from 2 to 10 μm. If the thickness is less than 1 μm, the adhesion to the metal plate becomes insufficient, which is not preferable. Conversely, if the thickness exceeds 15 μm, not only the adhesion to the metal plate is saturated, but also the film tends to wrinkle in the case of laminating the film with the metal plate or in the heat treatment step after can-making.

The polyester of the present invention may contain, if necessary, an antioxidant, a heat stabilizer, an ultraviolet absorber, a plasticizer, a pigment, an antistatic agent, a lubricant, a nucleating agent, a lubricant comprising inorganic or organic particles, and the like. May be.
The method for producing the polyester in the present invention is not particularly limited. That is, those produced by either the transesterification method or the direct polymerization method can be used. Further, it may be produced by a solid-phase polymerization method in order to increase the molecular weight. Further, a polyester having a low oligomer content produced by a vacuum solid-phase polymerization method is used in order to reduce the amount of oligomers from the polyester resin in a paste-lize treatment, a retort treatment, and the like, which are performed after filling the contents in a can. Is preferred.

ポ リ エ ス テ ル It is necessary that the melting point of the polyester used in the present invention is 180 ° C. or higher in order to ensure can-making properties (in a drawing or ironing process, the polyester film on the inner side of the can is released from the punch).

In the present invention, when extruding a polyester and an olefin-based polymer into a layer from a T-die,
It is preferable to use an olefin-based polymer at both ends (one side is 5 cm or less).
In the present invention, a polymer obtained by dry-blending or melt-mixing a polyester and an olefin-based polymer is melted in a known single-screw or twin-screw extruder, and then layered using a known multi-manifold die such as an edge lamination type. Is obtained.
In the present invention, as the cooling and solidifying method, a known method of contacting the molten resin in a layer form from a T-die with a rotated cooling roll can be used. When bringing the molten resin into contact with the cooling roll, it is preferable to employ a method of forcibly blowing air or a method of bringing the resin into close contact with static electricity. In both of the forced air spraying method and the electrostatic adhesion method, it is more preferable that both ends and the center of the layered resin are independently formed. Further, when the molten resin comes into contact with the cooling roll, it is more preferable to use a measure (for example, a device such as a vacuum chamber or a vacuum box) for reducing the entrained flow by reducing the pressure on the opposite side.
In the present invention, after solidification by cooling, the resin film obtained by cutting and removing both ends as necessary is subjected to longitudinal stretching of 1.3 to 6.0 times at a temperature not lower than the glass transition point of polyester, and then A heat treatment is performed under tension at a temperature of 50 ° C. or more and a melting point of the polyester of −20 ° C. for 1 to 20 seconds, and then both ends of the resin film are cut off to obtain a polyester film.
The polyester film used in the present invention needs to have a heat shrinkage in the longitudinal direction at 150 ° C. of 4 to 30%. If the heat shrinkage is less than 4%, the adhesion after lamination is undesirably reduced. Conversely, when the heat shrinkage exceeds 30%, wrinkles and blocking occur due to longitudinal shrinkage during storage until lamination, and wrinkles and bubbles are easily generated on the polyester film-coated metal plate, which is not preferable. .
In the present invention, as the metal plate, a surface-treated steel plate such as tin-free steel, a tin plate (tin-plated steel plate), a nickel-plated steel plate, an aluminum plate or an aluminum alloy plate, or a surface-treated aluminum plate or aluminum alloy plate can be used. After heating these metal plates to a melting point of polyester of -20 ° C. or higher and a melting point of + 150 ° C., a polyester film is laminated on the metal plate using a laminating roll. Subsequently, the laminated metal plate is heated to a melting point of polyester of + 10 ° C. or higher. After heating at a melting point of + 60 ° C., the resultant is cooled with water and / or air to obtain a metal plate coated with a polyester film. However, when laminating a polyester-based film on a metal plate, it is preferable that the C layer side and the metal plate are in contact with each other in order to ensure adhesion and can-making properties.

Hereinafter, the present invention will be described based on examples.
[Evaluation method]
(1) Melting Point and Glass Transition Point of Polyester A polyester composition was heated and melted at 300 ° C. for 5 minutes, and then quenched with liquid nitrogen. Using a 10 mg sample, a differential scanning calorimeter (DSC) was run in a nitrogen stream. When the exothermic / endothermic curve (DSC curve) is measured at a heating rate of 10 ° C./min using the melting point Tm (° C.) as the melting point Tm (° C.), the endothermic change curve between 0 and 100 ° C. Were drawn with two tangent lines, and the intersection was defined as the glass transition point Tg (° C.).
(2) Temperature drop crystallization temperature of polyester 10 mg of the polyester composition was heated and melted at 300 ° C. for 5 minutes in a nitrogen stream in a differential scanning calorimeter (DSC), and then continuously heated at a rate of 10 ° C./min. The peak temperature of the exothermic peak accompanying the crystallization when the curve (DSC curve) was measured was defined as the cooling crystallization temperature Tc2.
(3) Neck-in Amount The average value (Acm) of the width of the resin film after cooling and solidification (resin film width before cutting off both ends) measured at n = 3 and the discharge port width of the T die (60 cm) is used. The neck-in amount (cm) was determined by the following equation. A neck-in amount of 5 cm or less was evaluated as practical.
Neck-in amount (cm) = 60-A
(4) Appearance and cut resistance of roll film after storage After storing the roll film at 40 ° C. for one month under the condition of relative humidity of 80%, the appearance of the film and a tensile test according to JIS K 7127 (longitudinal direction) n = 30, No. 1 test piece of 15 mm width, test speed: 200 mm / min). The evaluation criteria were set as follows, and ○ was evaluated as practical.
[appearance]
：: No wrinkle, blocking, and thinning ×: With wrinkle, blocking, and thinning [cutting resistance]
Evaluated by the number of samples having a breaking elongation of <5%. (2/30 or less were evaluated as practical.)
(5) Heat shrinkage rate Evaluated according to JIS Z 1715.
(6) Preparation method of polyester-based film-coated metal plate A polyester-based film was laminated on one side of an aluminum alloy plate (3004 series alloy plate having a thickness of 0.26 mm) heated to 250 ° C, heated at 275 ° C, and then submerged in water. It was quenched to produce a laminated aluminum plate.
(7) Evaluation of can-making property A laminated aluminum plate was made at n = 10 so that the polyester-based film side became the inner surface, and the mold punch and the film were released, the film was peeled off, and cracks occurred on the can wall and the bottom of the can. The condition was visually observed.
(7) Heat resistance The aluminum laminated plate was cut into a piece of 5 cm x 5 cm, a weight of 100 g was placed on the film surface side of the section, and after heating at 200 ° C for 5 minutes, the appearance of traces of the weight was visually observed. The evaluation criteria were set as follows, and ○ was evaluated as practical.
：: Traces are not noticeable △: Traces are noticeable ×: Traces are noticeable (8) Evaluation of wrinkle generation after heat treatment 10 metal cans were heated in a hot air dryer at 200 ° C. for 5 minutes. The appearance of wrinkles later was visually observed.
[Abbreviations and contents of polyester and olefin-based polymers used in Examples and Comparative Examples]
(1) PET: polyethylene terephthalate (2) PBT: polybutylene terephthalate (3) PET-I (15): polyethylene terephthalate / isophthalate (d)
15 mol% of repeating units of tylene isophthalate)
(4) PET-I (22): polyethylene terephthalate / isophthalate (22 mol% of repeating units of ethylene isophthalate)
(5) PET-I (50): polyethylene terephthalate / isophthalate (50 mol% of ethylene isophthalate repeating unit)
(6) Polyester A: copolymerized polyester of terephthalic acid / isophthalic acid / adipic acid (65/10/25 mol%) and 1,4 butanediol
(7) Polyester B: Copolymerized polyester of terephthalic acid / dimer acid (91/9 mol%) and 1,4-butanediol (8) CO-PES: Terephthalic acid and ethylene glycol / cyclohexane dimethanol (70/30 mol) %) And low-density polyethylene (Sumikasen G401: trade name, manufactured by Sumitomo Chemical Co., Ltd.)
(10) Olefin B: linear low-density polyethylene (Sumitomo Chemical Co., Ltd., Sumikasen FV405: trade name)
(11) Olefin C: ethylene butene copolymer (Tuffmer A4085: trade name, manufactured by Mitsui Chemicals, Inc.)
(12) Olefin D: ionomer (manufactured by Du Pont-Mitsui Polychemicals, Himiran 1706: trade name)
(13) Olefin E: ethylene-methyl acrylate copolymer (EMAC SP2205, trade name, manufactured by Eastman Chemical Company)
(14) Olefin F: Polypropylene (manufactured by Sumitomo Chemical Co., Ltd., Noblen FS2011 DG2: trade name)

[Example 1]
70% by weight of PET as a raw material of layer A, PET-I (15) as raw material of layer B, 70% by weight of PET-I (22) and 30% by weight of polyester A are melted at 280 ° C. Olefin A alone is melted at 250 ° C as the raw material of the part, and an edge lamination type T die (olefin discharge port width / center discharge port width / olefin discharge port width = 2cm / 56cm / 2cm, heated to 260 ° C) ) And cast it into a layered cooling roll (peripheral speed 20 m / min) (distance from the T-die to the contact point of the molten resin on the cooling roll is 15 cm, and the center and both ends are forcibly aired by separate devices) ), The resin film (A) was longitudinally stretched 3.0 times at a preheating temperature of 65 ° C. and a stretching temperature of 100 ° C., and was heat-treated at 150 ° C. for 3 seconds using a clip gripping setter. Part winding to cut and removed (one 5 cm), a thickness of 25 [mu] m (A layer / B layer / C layer: 6/13 / 6μm) in length to obtain a roll-shaped polyester film of 100 m.
After storing the roll-shaped polyester film for one month at 40 ° C. and a relative humidity of 80%, the C-layer side of the polyester film was added to the 3004 aluminum alloy plate (0.26 mm thick) heated to 250 ° C. And heated to 275 ° C., followed by rapid cooling in water to obtain a laminated aluminum plate.
After applying the forming lubricant to the thus obtained laminated aluminum plate, the plate was heated and subjected to drawing at a plate temperature of 70 ° C. so that the polyester film was on the inner surface side. Next, the temperature of the obtained cup was set to 40 ° C., and ironing was performed at a mold temperature of 80 ° C. to obtain a 350 ml-sized seamless can.
Melting point of polyester, Glass transition point, Temperature crystallization temperature, Neck-in amount during casting, Heat shrinkage, Appearance and cut resistance of roll film after storage, Can making property (Releasability of processed punch, Film peeling state) Table 1 shows the state of wrinkles after heat treatment and heat resistance. The method of this example has a small neck-in amount, is excellent in economical efficiency, and has good laminating properties because there is no deterioration in appearance and cut resistance of the polyester film after storage, and can-making properties and heat resistance. It can be said that this is a method for producing a polyester-based film-coated metal plate which is excellent in wrinkles and hardly generates wrinkles by heat treatment after can-making.

[Example 2]
Rolled polyester film having a thickness of 25 μm (A layer / B layer / C layer: 6/13/6 μm) and a length of 100 m in the same manner as in Example 1 except that the raw material of the A layer of the resin film was PBT. Got.
Then, a laminated aluminum plate was prepared and made in the same manner as in Example 1 to obtain a 350 ml-sized seamless can.
Melting point of polyester, Glass transition point, Temperature crystallization temperature, Neck-in amount during casting, Heat shrinkage, Appearance and cut resistance of roll film after storage, Can making property (Releasability of processed punch, Film peeling state) Table 1 shows the state of wrinkles after heat treatment and heat resistance. The method of this example has a small neck-in amount, is excellent in economical efficiency, and has good laminating properties because there is no deterioration in appearance and cut resistance of the polyester film after storage, and can-making properties and heat resistance. It can be said that this is a method for producing a polyester-based film-coated metal plate which is excellent in wrinkles and hardly generates wrinkles by heat treatment after can-making.

[Example 3]
Roll-type polyester system having a thickness of 25 μm (A layer / B layer / C layer: 6/13/6 μm) and a length of 100 m in the same manner as in Example 1 except that the raw material of the A layer of the resin film was polyester B. A film was obtained.
Then, a laminated aluminum plate was prepared and made in the same manner as in Example 1 to obtain a 350 ml-sized seamless can.
Melting point of polyester, Glass transition point, Temperature crystallization temperature, Neck-in amount during casting, Heat shrinkage, Appearance and cut resistance of roll film after storage, Can making property (Releasability of processed punch, Film peeling state) Table 1 shows the state of wrinkles after heat treatment and heat resistance. The method of this example has a small neck-in amount, is excellent in economical efficiency, and has good laminating properties because there is no deterioration in appearance and cut resistance of the polyester film after storage, and can-making properties and heat resistance. It can be said that this is a method for producing a polyester-based film-coated metal plate which is excellent in wrinkles and hardly generates wrinkles by heat treatment after can-making.

[Example 4]
Except that the raw material of the B layer of the resin film was PET-I (22), the thickness was 25 μm (A layer / B layer / C layer: 6/13/6 μm) and the length was 100 m as in Example 1. A roll-shaped polyester film was obtained.
Then, a laminated aluminum plate was prepared and made in the same manner as in Example 1 to obtain a 350 ml-sized seamless can.
Melting point of polyester, Glass transition point, Temperature crystallization temperature, Neck-in amount during casting, Heat shrinkage, Appearance and cut resistance of roll film after storage, Can making property (Releasability of processed punch, Film peeling state) Table 1 shows the state of wrinkles after heat treatment and heat resistance. The method of this example has a small neck-in amount, is excellent in economical efficiency, and has good laminating properties because there is no deterioration in appearance and cut resistance of the polyester film after storage, and can-making properties and heat resistance. It can be said that this is a method for producing a polyester-based film-coated metal plate which is excellent in wrinkles and hardly generates wrinkles by heat treatment after can-making.

[Example 5]
The thickness was 25 μm (A layer / B layer / C layer: 6/13 /) as in Example 1 except that the raw material of the B layer of the resin film was 80% by weight of PET-I (22) and 20% by weight of PBT. 6 μm) and a roll-shaped polyester film having a length of 100 m was obtained.
Then, a laminated aluminum plate was prepared and made in the same manner as in Example 1 to obtain a 350 ml-sized seamless can.
Melting point of polyester, Glass transition point, Temperature crystallization temperature, Neck-in amount during casting, Heat shrinkage, Appearance and cut resistance of roll film after storage, Can making property (Releasability of processed punch, Film peeling state) Table 1 shows the state of wrinkles after heat treatment and heat resistance. The method of this example has a small neck-in amount, is excellent in economical efficiency, and has good laminating properties because there is no deterioration in appearance and cut resistance of the polyester film after storage, and can-making properties and heat resistance. It can be said that this is a method for producing a polyester-based film-coated metal plate which is excellent in wrinkles and hardly generates wrinkles by heat treatment after can-making.

[Example 6]
The thickness was 25 μm (A layer / B layer / C layer: 6/13) in the same manner as in Example 1 except that the raw material of the B layer of the resin film was 87% by weight of PET-I (15) and 13% by weight of olefin A. / 6 μm) and a roll-shaped polyester film having a length of 100 m.
Then, a laminated aluminum plate was prepared and made in the same manner as in Example 1 to obtain a 350 ml-sized seamless can.
Melting point of polyester, Glass transition point, Temperature crystallization temperature, Neck-in amount during casting, Heat shrinkage, Appearance and cut resistance of roll film after storage, Can making property (Releasability of processed punch, Film peeling state) Table 1 shows the state of wrinkles after heat treatment and heat resistance. The method of this example has a small neck-in amount, is excellent in economical efficiency, and has good laminating properties because there is no deterioration in appearance and cut resistance of the polyester film after storage, and can-making properties and heat resistance. It can be said that this is a method for producing a polyester-based film-coated metal plate which is excellent in wrinkles and hardly generates wrinkles by heat treatment after can-making.

[Example 7]
The thickness of the resin layer was 25 μm in the same manner as in Example 1 except that the raw material of the layer B was 87% by weight of PET-I (15) and 13% by weight of olefin B, and the raw materials at both ends of the resin film were olefin B alone. (A layer / B layer / C layer: 6/13/6 μm) to obtain a roll-shaped polyester film having a length of 100 m.
Then, a laminated aluminum plate was prepared and made in the same manner as in Example 1 to obtain a 350 ml-sized seamless can.
Melting point of polyester, Glass transition point, Temperature crystallization temperature, Neck-in amount during casting, Heat shrinkage, Appearance and cut resistance of roll film after storage, Can making property (Releasability of processed punch, Film peeling state) Table 1 shows the state of wrinkles after heat treatment and heat resistance. The method of this example has a small neck-in amount, is excellent in economical efficiency, and has good laminating properties because there is no deterioration in appearance and cut resistance of the polyester film after storage, and can-making properties and heat resistance. It can be said that this is a method for producing a polyester-based film-coated metal plate which is excellent in wrinkles and hardly generates wrinkles by heat treatment after can-making.

[Example 8]
The thickness of the resin layer was 25 μm in the same manner as in Example 1 except that the raw material of the B layer of the resin film was 87% by weight of PET-I (15) and 13% by weight of olefin C, and the raw materials at both ends of the resin film were olefin C alone. (A layer / B layer / C layer: 6/13/6 μm) to obtain a roll-shaped polyester film having a length of 100 m.
Then, a laminated aluminum plate was prepared and made in the same manner as in Example 1 to obtain a 350 ml-sized seamless can.
Melting point of polyester, Glass transition point, Temperature crystallization temperature, Neck-in amount during casting, Heat shrinkage, Appearance and cut resistance of roll film after storage, Can making property (Releasability of processed punch, Film peeling state) Table 1 shows the state of wrinkles after heat treatment and heat resistance. The method of this example has a small neck-in amount, is excellent in economical efficiency, and has good laminating properties because there is no deterioration in appearance and cut resistance of the polyester film after storage, and can-making properties and heat resistance. It can be said that this is a method for producing a polyester-based film-coated metal plate which is excellent in wrinkles and hardly generates wrinkles by heat treatment after can-making.

[Example 9]
The thickness of the resin layer was 25 μm in the same manner as in Example 1 except that the raw material of the layer B of the resin film was 87% by weight of PET-I (15) and 13% by weight of olefin D, and the raw materials at both ends of the resin film were olefin D alone. (A layer / B layer / C layer: 6/13/6 μm) to obtain a roll-shaped polyester film having a length of 100 m.
Then, a laminated aluminum plate was prepared and made in the same manner as in Example 1 to obtain a 350 ml-sized seamless can.
Melting point of polyester, Glass transition point, Temperature crystallization temperature, Neck-in amount during casting, Heat shrinkage, Appearance and cut resistance of roll film after storage, Can making property (Releasability of processed punch, Film peeling state) Table 1 shows the state of wrinkles after heat treatment and heat resistance. The method of this example has a small neck-in amount, is excellent in economical efficiency, and has good laminating properties because there is no deterioration in appearance and cut resistance of the polyester film after storage, and can-making properties and heat resistance. It can be said that this is a method for producing a polyester-based film-coated metal plate which is excellent in wrinkles and hardly generates wrinkles by heat treatment after can-making.

[Example 10]
The raw material of the layer B of the resin film is 87% by weight of PET-I (15) and 13% by weight of an olefin comprising olefin A / olefin E = 70/30 (% by weight). A roll having a thickness of 25 μm (layer A / layer B / layer C: 6/13/6 μm) and a length of 100 m in the same manner as in Example 1 except that the olefin was made of olefin E = 70/30 (% by weight). A polyester film was obtained.
Then, a laminated aluminum plate was prepared and made in the same manner as in Example 1 to obtain a 350 ml-sized seamless can.
Melting point of polyester, Glass transition point, Temperature crystallization temperature, Neck-in amount during casting, Heat shrinkage, Appearance and cut resistance of roll film after storage, Can making property (Releasability of processed punch, Film peeling state) Table 1 shows the state of wrinkles after heat treatment and heat resistance. The method of this example has a small neck-in amount, is excellent in economical efficiency, and has good laminating properties because there is no deterioration in appearance and cut resistance of the polyester film after storage, and can-making properties and heat resistance. It can be said that this is a method for producing a polyester-based film-coated metal plate which is excellent in wrinkles and hardly generates wrinkles by heat treatment after can-making.

[Example 11]
The raw material for the layer B of the resin film was obtained by granulating 85% by weight of PET-I (15) and both ends (85% by weight of olefin A) cut and removed before obtaining a polyester film in Example 1. Rolled polyester film having a thickness of 25 μm (A layer / B layer / C layer: 6/13/6 μm) and a length of 100 m was obtained in the same manner as in Example 1 except that the amount of the polymer was changed to 15% by weight. .
Then, a laminated aluminum plate was prepared and made in the same manner as in Example 1 to obtain a 350 ml-sized seamless can.
Melting point of polyester, Glass transition point, Temperature crystallization temperature, Neck-in amount during casting, Heat shrinkage, Appearance and cut resistance of roll film after storage, Can making property (Releasability of processed punch, Film peeling state) Table 1 shows the state of wrinkles after heat treatment and heat resistance. The method of this example has a small neck-in amount, is excellent in economical efficiency, and has good laminating properties because there is no deterioration in appearance and cut resistance of the polyester film after storage, and can-making properties and heat resistance. It can be said that this is a method for producing a polyester-based film-coated metal plate which is excellent in wrinkles and hardly generates wrinkles by heat treatment after can-making.

[Comparative Example 1]
An attempt was made to obtain a roll-shaped resin film in the same manner as in Example 1 except that PET was used as the raw material at both ends of the resin film. However, if the neck-in amount was large and both ends were not cut and removed by 18 cm, the thickness distribution was reduced. However, since a uniform central portion cannot be obtained, it can be said that this is a method of producing a polyester film-coated metal plate which is inferior in economic efficiency.
Table 2 shows the melting point, glass transition point, cooling crystallization temperature, and neck-in amount during casting of the polyester.

[Comparative Example 2]
A roll-shaped polyester film having a thickness of 25 μm (layer A / layer B: 6/19 μm) and a length of 100 m was obtained in the same manner as in Example 1 except that the layer C was not provided.
Then, a laminated aluminum plate was prepared and made in the same manner as in Example 1 to obtain a 350 ml-sized seamless can.
Melting point of polyester, Glass transition point, Temperature crystallization temperature, Neck-in amount during casting, Heat shrinkage, Appearance and cut resistance of roll film after storage, Can making property (Releasability of processed punch, Film peeling state) , Cracks) are shown in Table 2. This method is not preferable as a method for producing a polyester film-coated metal sheet because of poor can-making properties.

[Comparative Example 3]
A roll-shaped polyester film having a thickness of 25 μm (A layer / C layer: 6/19 μm) and a length of 100 m was obtained in the same manner as in Example 1 except that the B layer was not provided.
Then, a laminated aluminum plate was prepared and made in the same manner as in Example 1 to obtain a 350 ml-sized seamless can.
Melting point of polyester, Glass transition point, Temperature crystallization temperature, Neck-in amount during casting, Heat shrinkage, Appearance and cut resistance of roll film after storage, Can making property (Releasability of processed punch, Film peeling state) Table 2 shows the state of wrinkles after heat treatment and heat resistance. This method is not preferable as a method for producing a polyester-based film-coated metal sheet because heat resistance is slightly inferior and wrinkles are easily generated in heat treatment after can-making.

[Comparative Example 4]
A roll-like polyester film having a thickness of 25 μm (layer B / C layer: 19/6 μm) and a length of 100 m was obtained in the same manner as in Example 1 except that the layer A was not provided.
Then, a laminated aluminum plate was prepared and made in the same manner as in Example 1 to obtain a 350 ml-sized seamless can.
Melting point of polyester, Glass transition point, Temperature crystallization temperature, Neck-in amount during casting, Heat shrinkage, Appearance and cut resistance of roll film after storage, Can making property (Releasability of processed punch, Film peeling state) Table 2 shows the heat resistance. This method is not preferable as a method for producing a polyester-based film-coated metal sheet because of poor can-making properties and heat resistance.

[Comparative Example 5]
Roll-shaped polyester having a thickness of 25 μm (A layer / B layer / C layer: 6/13/6 μm) and a length of 100 m in the same manner as in Example 1 except that CO-PES was used as the raw material of the C layer of the resin film. A system film was obtained.
Next, a laminated aluminum plate was prepared in the same manner as in Example 1. However, when heated to 275 ° C. after lamination, wrinkles occurred, which is not preferable as a method for producing a polyester film-coated metal plate.
Table 2 shows the melting point, the glass transition point, the crystallization temperature during cooling, the neck-in amount during casting, the heat shrinkage, the appearance of the roll film after storage, and the cut resistance of the polyester.

[Comparative Example 6]
Except for using 60% by weight of PET and 40% by weight of PET-I (50) as raw materials for the A layer of the resin film, the thickness was 25 μm (A layer / B layer / C layer: 6/13 / 6 μm) and a roll-shaped polyester film having a length of 100 m was obtained.
Then, a laminated aluminum plate was prepared and made in the same manner as in Example 1 to obtain a 350 ml-sized seamless can.
Melting point of polyester, Glass transition point, Temperature crystallization temperature, Neck-in amount during casting, Heat shrinkage, Appearance and cut resistance of roll film after storage, Can making property (Releasability of processed punch, Film peeling state) Table 2 shows the heat resistance. This method is not preferable as a method for producing a polyester-based film-coated metal sheet because of poor can-making properties and heat resistance.

[Comparative Example 7]
The thickness was 25 μm (A layer / B layer / C layer: 6/13/6 μm) in the same manner as in Example 1 except that 50% by weight of polyester A and 50% by weight of olefin A were used as raw materials for layer B of the resin film. A roll-shaped polyester film having a length of 100 m was obtained.
Then, a laminated aluminum plate was prepared and made in the same manner as in Example 1 to obtain a 350 ml-sized seamless can.
Melting point of polyester, Glass transition point, Temperature crystallization temperature, Neck-in amount during casting, Heat shrinkage, Appearance and cut resistance of roll film after storage, Can making property (Releasability of processed punch, Film peeling state) Table 2 shows the heat resistance. This method is not preferable as a method for producing a polyester film-coated metal sheet because of poor can-making properties.

[Comparative Example 8]
A roll-shaped polyester unstretched film having a thickness of 25 μm (layer A / layer B / layer C: 6/13/6 μm) and a length of 100 m was obtained from the raw material of Example 1.
Table 2 shows the melting point, the glass transition point, the crystallization temperature during cooling, the neck-in amount during casting, the heat shrinkage, the appearance of the roll film after storage, and the cut resistance of the polyester.
As a result of storage in the same manner as in Example 1, the cut resistance of the film is poor, wrinkle-tarmi blocking occurs, and a laminated aluminum plate having a good appearance cannot be obtained. Not preferred.

[Comparative Example 9]
Rolled polyester film having a thickness of 25 μm (A layer / B layer / C layer: 6/13/6 μm) and a length of 100 m in the same manner as in Example 1 except that the heat treatment temperature after longitudinal stretching was 190 ° C. Got.
Then, a laminated aluminum plate was prepared and made in the same manner as in Example 1 to obtain a 350 ml-sized seamless can.
Melting point of polyester, Glass transition point, Temperature crystallization temperature, Neck-in amount during casting, Heat shrinkage, Appearance and cut resistance of roll film after storage, Can making property (Releasability of processed punch, Film peeling state) , Cracks) are shown in Table 2. This method is not preferable as a method for producing a polyester film-coated metal sheet because of poor can-making properties.

[Comparative Example 10]
A roll-like polyester film having a thickness of 25 μm (A layer / B layer / C layer: 6/13/6 μm) and a length of 100 m was obtained in the same manner as in Example 1 except that the heat treatment was not performed after the longitudinal stretching. Was.
Table 2 shows the melting point, the glass transition point, the crystallization temperature during cooling, the neck-in amount during casting, the heat shrinkage, the appearance of the roll film after storage, and the cut resistance of the polyester.
This method is not preferable as a method for producing a metal film coated with a polyester film, since a wrinkle in the lateral direction of the film and tarnish are generated at both ends of the film, and a laminated aluminum plate having a good appearance cannot be obtained.

[Comparative Example 11]
Casting was performed in the same manner as in Example 1 except that the raw material of the layer B of the resin film was 87% by weight of PET-I (15) and 13% by weight of olefin F, and the raw materials at both ends of the resin film were olefin F alone. This method is not preferable as a method for producing a polyester film-coated metal plate because of its large neck-in amount. Table 2 shows the melting point, glass transition point, cooling crystallization temperature, and neck-in amount during casting of the polyester. This method is not economical because of a large neck-in amount and is not preferred as a method for producing a polyester film-coated metal plate.

According to the present invention, the method for producing a polyester film-coated metal sheet is not only an economical production method because it is possible to reduce waste of raw materials, but also has a can-making property (a releasing property of a processing punch, adhesion of a film, and resistance to film resistance). Since a polyester film-coated metal sheet having excellent cracking properties and heat resistance can be obtained, it can be widely used as a method for producing a polyester film-coated metal sheet for forming a metal can, and greatly contributes to the industry. .

Claims (3)

In a manufacturing method in which a metal plate is coated with a polyester having a melting point of 180 ° C. or more, a resin film obtained by cooling and solidifying a molten resin film obtained in a state where an olefin polymer is merged at both ends using a T-die is vertically stretched. Uniaxially stretching in the direction, then heat-setting, and then cutting and removing both ends to obtain a polyester film, and laminating the polyester film to a metal plate heated in a separate step A method for producing a coated metal plate, wherein a polyester film is composed of an A layer, a B layer, and a C layer, the A layer is made of polyester having a temperature-reducing crystallization temperature of 150 ° C. or more, and the B layer has a melting point of 190 to 190 ° C. The polyester and the olefin-based polymer having a glass transition temperature of 225 ° C and a glass transition temperature of 50 ° C or higher consist of 70:30 to 100: 0 (% by weight). A polyester film-coated metal sheet comprising a polyester having a transfer temperature of 30 to 50 ° C., and wherein the polyester film has a heat shrinkage in the longitudinal direction at 150 ° C. of 4 to 30%. Manufacturing method. (4) A method for producing a metal film coated with a polyester film, wherein both ends of the molten resin film according to (1) and the olefin polymer in the layer B are the same. 方法 A method for producing a metal sheet coated with a polyester film, wherein the olefin polymer according to claim 1 is polyethylene and / or an ethylene copolymer.