JP2002088233A - Polyester film for metal sheet lamination, laminated metal sheet, and metal container using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyester film for metal sheet lamination which is excellent in thermal lamination properties and moldability, especially moldability of a high order, such as draw molding or strip molding, in resistances to impact and retorting, and in preserving taste and fragrance and which is suitable for covering a metal can. SOLUTION: This film comprises (A) 80-40 mass% polybutylene terephthalate having a melting point of 200-230 deg.C or polyester mainly comprising the same and (B) 20-60 mass% polyethylene terephthalate having a melting point of 230-256 deg.C or polyester mainly comprising the same. The transesterification index of the film is 7 or lower.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester film for laminating a metal plate, a film-laminated metal plate and a metal container using the same, and more particularly, to a film-laminated metal plate obtained by laminating a polyester resin on a metal plate. The present invention relates to a polyester film useful as a material used for drawing and ironing, and a film-laminated metal plate and a metal container using the same.

[0002]

2. Description of the Related Art Conventionally, a solvent type paint mainly composed of a thermosetting resin has been applied for the purpose of preventing corrosion of the inner and outer surfaces of a metal can. However, solvent-type paints require heating at a high temperature to form a coating film, and a large amount of solvent is generated at that time, and thus there is a problem in terms of work safety and the environment. Therefore, recently, as a corrosion prevention method using no solvent, coating of a metal plate with a thermoplastic resin has been proposed,
Among the thermoplastic resins, polyester is particularly excellent in processability, heat resistance, and the like. Therefore, a polyester-based film for laminating a metal plate is being developed.

[0003] As a method of coating a film on a metal plate, there are a method of melting a thermoplastic resin and extruding it directly onto a metal, and a method of thermocompression bonding a thermoplastic resin film directly or through an adhesive. Above all, a method using a thermoplastic resin film is considered to be an effective method because the handling of the resin is easy, the workability is excellent, and the uniformity of the resin film thickness is also excellent. In addition, since the method using an adhesive has environmental and cost problems, a method of directly thermocompression bonding a film is advantageous and attracts attention.

[0004] A metal can coated with a thermoplastic resin film is formed by laminating a thermoplastic resin film on a metal plate such as a steel plate or an aluminum plate (including a plate subjected to a surface treatment such as plating). Manufactured.
The thermoplastic resin film used in such applications has good heat laminating properties with a metal plate and excellent moldability of the can, that is, peeling, cracking, pinholes, etc. of the film at the time of molding the can. Various properties are required at the same time, such as no generation of odor, no embrittlement during printing after can molding, retort sterilization treatment and long-term storage, and excellent content and flavor retention of the contents.

As such a polyester film for laminating a metal plate, there has been proposed a method in which other components are mixed or copolymerized for the purpose of imparting heat lamination properties and improving the moldability of a can. For example, (a) a copolymer of polyethylene terephthalate (PET) with other components is disclosed in Japanese Patent Publication No. H8-19245 and Japanese Patent Publication No. H8-192.
No. 46, Japanese Patent No. 2528204, etc.
(B) Copolyester 99 having ethylene terephthalate having a melting point of 210 to 245 ° C. as a main repeating unit
No. 2,851,468, which is a mixture of 〜60% by weight and PBT or a copolymer thereof of 1 to 40% by weight.
JP-A-5-186612, JP-A-5-18661
No. 3 each discloses it. Further, (c) a multilayer film including a layer in which 99 to 50% by weight of a copolymerized polyester having ethylene terephthalate having a melting point of 210 to 245 ° C. as a main repeating unit and 1 to 50% by weight of PBT or a copolymer thereof, JP-A-10-315412 and JP-A-11-207909 disclose those having an ester exchange rate of 3% or more.

However, in (a), the thermal lamination property and moldability are improved by copolymerizing PET and lowering the melting point and lowering the crystallization, but the embrittlement occurs during the heat treatment after can molding and the retort sterilization treatment. There is a problem that impact resistance is reduced. In (b), by blending a PBT-based resin, the heat laminating property and the above-mentioned embrittlement and impact resistance of the can are improved, but the heat laminating property and adhesion to metal are not sufficient. Higher-order workability such as drawing and ironing was not sufficient. In (c),
The purpose of the present invention is to improve the impact resistance, especially at low temperatures, by using a mixture of a PBT resin and a PET resin and making the degree of transesterification thereof a certain value or more. Was not sufficient, and it was necessary to laminate a PET-based copolymerized polyester layer on the side in contact with the contents in order to improve the fragrance retention.

On the other hand, the present inventors have previously described PB
T or polyester (A) 90-based mainly on T
A biaxially stretched film comprising 45% by mass and 10 to 55% by mass of PET or a polyester (B) containing the same as a main component has been proposed (JP-A-9-194604,
JP-A-10-110046). The film proposed here has a high degree of crystallinity and can be thermocompression-bonded at a relatively low temperature, and the obtained laminated metal plate has excellent workability. In addition, even after retort sterilization and long-term storage, the film does not become brittle and has excellent impact resistance, but during high-order processing such as drawing and ironing, processing parts with severe deformation In some cases, the film was whitened or microcracks occurred.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to provide excellent heat lamination properties with a metal plate, high moldability of cans, especially high-order workability such as drawing and ironing, and furthermore, preservation of the content. An object of the present invention is to provide a polyester film for laminating a metal plate, a laminated metal plate, and a metal can using the same, which are suitable for a film-laminated metal can excellent in fragrance.

[0009]

Means for Solving the Problems The present inventors have conducted intensive studies in order to solve the above-mentioned problems, and as a result, have found that two crystals having different crystallinities have different properties.
A film comprising a specific blending ratio of at least one kind of polyester, that is, a polyester (A) mainly composed of PBT and a polyester (B) mainly composed of PET, wherein the degree of transesterification between polyester (A) and polyester (B) is determined. By using a polyester film adjusted to a specific range, a metal can with excellent heat lamination properties with metal, moldability of cans, especially excellent in draw molding and ironing molding, and also excellent impact resistance, taste retention and fragrance retention. They have found that they can be manufactured and arrived at the present invention.

That is, the gist of the present invention is as follows. Polybutylene terephthalate having a melting point of 200 to 223 ° C., or a polyester (A) mainly containing the same
A metal comprising 40% by mass and 20 to 60% by mass of polyethylene terephthalate having a melting point of 230 to 256 ° C. or polyester (B) containing the same as a main component, and having a transesterification index of 7 or less. Polyester film for board lamination.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. In the present invention, the PBT-based polyester (A) is PBT and is obtained by copolymerizing other components with PBT. The melting point needs to be 200 to 223 ° C, and the melting point is lower than 200 ° C. And the heat resistance of the film decreases. In the case of using copolymerized PBT, the copolymerization ratio may be such that the melting point is within the above range, and 1,4-butanediol is preferably at least 80 mol%, particularly preferably at least 90 mol%, based on all alcohol components. 1,4
If the butanediol is less than 80 mol%,
In particular, the crystallization rate decreases, and the impact resistance after retort treatment decreases.

The copolymerization component is not particularly limited. Examples of the acid component include isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, 5-sodium sulfoisophthalic acid, oxalic acid, succinic acid, adipic acid, sebacic acid, and the like.
Azelaic acid, dodecane diacid, dimer acid, maleic anhydride, maleic acid, fumaric acid, itaconic acid, citraconic acid, mesaconic acid, dicarboxylic acids such as cyclohexanedicarboxylic acid, 4-hydroxybenzoic acid, ε-caprolactone, lactic acid and the like. No. Further, as the alcohol component, ethylene glycol, diethylene glycol,
1,3-propanediol, neopentyl glycol,
Examples include 1,6-hexanediol, cyclohexanedimethanol, triethylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and ethylene oxide adducts of bisphenol A and bisphenol S. In addition, trimellitic acid, trimesic acid, pyromellitic acid, trimethylolpropane, glycerin, pentaerythritol, etc.
A small amount of a functional compound or the like may be used. Two or more of these copolymer components may be used in combination.

As the polyester (B) mainly composed of PET in the film of the present invention, PET and those obtained by copolymerizing other components with PET can be mentioned, and the melting point is in the range of 230 to 256 ° C. Is required,
It is more preferably in the range of 246 to 256 ° C. If the melting point is lower than 230 ° C., the crystallinity is reduced, whitening or white spots are generated after the retort treatment, and the impact resistance after the retort treatment is reduced. In particular, the melting point of the polyester (B) is 24
When the temperature is 6 ° C. or higher, heat resistance, impact resistance after retort treatment, and impact resistance after long-term storage are improved.

The component which can be copolymerized with PET is not particularly limited, and examples thereof include the same compounds as polyester (A).

The limiting viscosities of the raw material polyesters used for producing the polyester film of the present invention are 0.6 to 1.6 for the polyester (A) and 0.6 for the polyester (B).
Is preferably 0.5 to 0.9, and the intrinsic viscosity after melt mixing is 0.6 to 1.0, particularly preferably 0.75 to 1.0. When the intrinsic viscosity is less than the above range, the practical performance of the film is insufficient, and in particular, the film may be broken or cracked during high-order processing of the can. On the other hand, when the intrinsic viscosity exceeds the above range, the productivity of the film decreases, and the heat laminability of the film to the metal plate is impaired.

The method of polymerizing the raw material polyester is not particularly limited. For example, it can be polymerized by a transesterification method, a direct polymerization method or the like. As a transesterification catalyst, Mg,
Examples include oxides and acetates of Mn, Zn, Ca, Li, and Ti. As the polycondensation catalyst, Sb, Ti, G
e. Compounds such as oxides and acetates. Since the polyester after polymerization contains monomers and oligomers, by-products such as acetaldehyde and tetrahydrofuran, it is preferable to carry out solid-phase polymerization at a temperature of 200 ° C. or more under reduced pressure or an inert gas flow.

In the polymerization of the polyester, if necessary, additives such as an antioxidant, a heat stabilizer, an ultraviolet absorber,
An antistatic agent or the like can be added. As antioxidants, for example, hindered phenol compounds, hindered amine compounds, etc., as heat stabilizers, for example, phosphorus compounds, etc., as ultraviolet absorbers, for example, benzophenone compounds, benzotriazole compounds, etc. Can be mentioned.

In the present invention, the polyester (A) and the polyester (B) are obtained by mixing (A) / (B) = 80-40 /
20 to 60 (% by mass), preferably (A) / (B) = 8
0-55 / 20-45 (% by mass), more preferably (A) / (B) = 70-55 / 30-45 (% by mass). When the content of the polyester (A) exceeds 80% by mass, the properties of the polyester (A) having high crystallinity are remarkably exhibited, the moldability of the film-laminated metal plate is reduced, and the impact resistance is also deteriorated. When the content of the polyester (A) is less than 40% by mass, the crystallization rate decreases, and the physical properties after the retort treatment decrease. In particular, when the content of the polyester (A) is in the range of 55 to 70% by mass, the formability, impact resistance, and physical properties after retort treatment of the laminated metal sheet are balanced, which is a preferable embodiment.

The film of the present invention comprises a polyester (A)
Transesterification index of (B) and (B) (measuring method described in Examples)
Must be 7% or less, more preferably 5% or less. The transesterification rate increases, and the randomization of the components of the polyesters (A) and (B) proceeds. In particular, when the transesterification index exceeds 7%, the moldability of the laminate can deteriorates, and the Breakage and cracks are likely to occur, and the impact resistance after retort treatment is also reduced.

The film of the present invention preferably has a PBT residual index of 40 to 75% (the measuring method is described in Examples). If the residual index of PBT is less than 40%, the corrosion resistance of the can is reduced, and the flavor and aroma retention may be reduced. On the other hand, if it is larger than 75%, the adhesion of the film after the retort treatment is reduced, and the impact resistance may be reduced.

The method for adjusting the transesterification index to be within the above range is not particularly limited, but may include adjusting the melting temperature of the polyesters (A) and (B) in the extruder and adjusting the residence time in the extruder. Method. The method of melt-mixing is not particularly limited, and includes a method of mixing and melting the blended raw material chips in the same extruder, a method of mixing after melting each in a separate extruder, and the like. From the viewpoint of the latter, the latter method is preferable.

The film of the present invention preferably has a crystallization peak temperature (Tc) of 60 to 100 ° C., preferably 60 to 90 ° C. from an amorphous state. T
When c exceeds 100 ° C., the film tends to become brittle during the retort sterilization treatment, causing white spots to deteriorate the appearance of the film. On the other hand, when Tc is lower than 60 ° C., the moldability of the laminated metal sheet may be reduced when the molding temperature is high, and the content may have poor flavor and aroma.

Further, the film of the present invention has a thickness of 60 to 100.
The specific heat capacity (Cp) at 0 ° C is preferably 0 J / g · ° C or more. When Cp is less than 0 J / g · ° C., the crystallization speed near the crystallization start temperature becomes too fast, the formability deteriorates, whitening occurs during drawing or ironing, or pinholes occur. And cracks are likely to occur. Where 60
１００100 ° C. is a temperature range in which can molding is usually performed.

The method for producing the film of the present invention includes, for example, dry-blended polyesters (A) and (B).
Is supplied to an extruder equipped with a T-die, melt-mixed at a temperature of 250 to 280 ° C. for 3 to 15 minutes, and extruded into a sheet.
This sheet is closely contacted on a cooling drum adjusted to a temperature of room temperature or less and cooled, and the obtained unstretched sheet is pre-stretched by about 1 to 1.2 times in the machine direction (MD) as necessary.
Thereafter, the film is biaxially stretched by a tenter at a temperature of 50 to 150 ° C. in the MD and transverse direction (TD) so as to have a draw ratio of about 2 to 4 times, and further, the relaxation rate of the TD is set to several percent, and It can be manufactured by performing a heat treatment at 220 ° C. for several seconds. As the biaxial stretching method, a sequential or simultaneous biaxial stretching method can be used.

The heat treatment after stretching is a necessary step for imparting dimensional stability to the film. Examples of the method include a method of blowing hot air, a method of irradiating infrared rays, and a method of irradiating microwaves. A known method can be used. Among them, the method of blowing hot air is optimal because heating can be performed uniformly and accurately.

In order to improve the processability during film production and can production, it is desirable to add a small amount of an inorganic lubricant such as silica, alumina, kaolin or the like to form a film to impart slip properties to the film surface. Furthermore, in order to improve the appearance and printability of the film, for example, the film may contain a silicone compound or the like. Also, in order to improve laminating properties with metal and further increase strength,
An optional coating layer such as an adhesive layer may be formed by in-line coating during film production or post-coating after film production.

The polyester film of the present invention comprises a steel plate,
It is heat-laminated on a metal plate such as aluminum, but the metal plate to be laminated is chemically treated such as chromic acid treatment, phosphoric acid treatment, electrolytic chromic acid treatment, chromate treatment, nickel, tin, zinc, aluminum, gunmetal, brass Alternatively, a steel plate subjected to other various plating treatments or the like can be used.

Next, the present invention will be described specifically with reference to examples. The raw materials of the films and the methods for measuring the characteristic values in the examples and comparative examples are as follows.

(1) Raw Materials The details of the resin raw materials used in Examples and Comparative Examples are shown below. Component (A) A-1: PBT subjected to solid-state polymerization, IV 1.08 dl /
g, Tm 223 ° C. Contains 40ppm of Ti catalyst. A-2: PBT subjected to solid-state polymerization, IV 0.94 / g,
Tm 223 ° C. Contains 100ppm of Ti catalyst. A-3: Sebacic acid (SEA) 5mo subjected to solid state polymerization
1% copolymerized PBT, IV 0.92 dl / g, Tm217
° C. Contains 40ppm of Ti catalyst. A-4: SEA 12 mol% copolymerized PBT, IV 0.9
5 dl / g, Tm 204 ° C. Not subjected to solid-state polymerization.
Component (B) containing 40 ppm of Ti catalyst B-1: PET subjected to solid-state polymerization, IV 0.75 dl /
g, Tm 255 ° C., containing 40 ppm of Ge catalyst B-2: PET subjected to solid-state polymerization, IV 0.64 dl /
g, Tm 255 ° C., containing 100 ppm of Sb catalyst B-3: Isophthalic acid (IPA) 5 mol% copolymerized PE
T, IV 0.81 dl / g, Tm 243 ° C., not subjected to solid-state polymerization. Sb catalyst 10
Contains 0 ppm. B-4: IPA 12 mol% copolymerized PET, IV 0.6
5 dl / g, Tm 226 ° C., not subjected to solid-state polymerization.
Contains 100 ppm of Sb catalyst. The polyester resin is filled with silica having an average particle diameter of 1.1 μm at 0.1 wt%. (2) Measurement method A. Intrinsic Viscosity (IV) Using an equal weight mixed solvent of phenol / ethane tetrachloride,
It was determined from the solution viscosity measured at a temperature of 20 ° C. and a concentration of 0.5 g / dl. B. Transesterification index (Ex) and PBT residual index (Ea) ¹³ C NMR using a Varian GEMINI 2000/300 nuclear magnetic resonance apparatus (magnetic field strength 7.05 T).
Was measured. The measurement sample is a film 60 to 10
A solution obtained by dissolving 0 mg in 0.7 ml of CF ₃ COOD solvent was used, and both indices were obtained from the integrated values of peaks (FIG. 2) caused by transesterification according to the following formula. Ex = (Sab + Sba) / (Saa + Sbb + Sab + Sba) ×
100 (%) Ea = Saa / (Saa + Sbb + Sab + Sba) × 100
(%) C.I. Melting point (Tm) and elevated temperature crystallization peak temperature (Tc) Using Perkin Elmer DSC, 20 ° C. /
In minutes, the melting point and the crystallization peak temperature at the time of temperature rise were measured. As a measurement sample of the film, a stretched film was melted and then rapidly cooled at a rate of 100 ° C./min or more to be in an amorphous state. D. Specific heat capacity (Cp) JISK using Perkin Elmer DSC
It was measured according to 7123-1987. Sapphire was used as a standard. As a measurement sample, a stretched film was melted and then rapidly cooled at a rate of 100 ° C./min or more to be in an amorphous state. E. FIG. Heat laminating property Between heated metal roll and silicon rubber roll,
A sample film and a tin-free steel plate having a thickness of 0.21 mm are supplied in a superimposed manner, heated and bonded at a speed of 20 m / min and a linear pressure of 50 kgf / cm, immersed in ice water after 2 sec, cooled and laminated metal plate I got From the obtained laminate, eleven strip-shaped test pieces having a width of 18 mm (ends were not laminated and the laminated portion was secured to the MD by 8 cm or more) were cut out into TDs. Next, JIS Z-1522 was applied to the film surface of this test piece.
The adhesive tape specified in (1) was adhered, a 180 ° peel test was performed at a speed of 10 mm / min with an autograph manufactured by Shimadzu Corporation, and the peel strength was measured to evaluate the adhesiveness according to the following criteria. . A: The peel strength of 10 or more test pieces is 300 gf or more, or the film is broken at 300 gf or more. ：: The peel strength of 5 to 9 test pieces was 300 gf or more, or the film was broken at 300 gf or more. Δ: 7 or more test pieces having a peel strength of less than 300 gf. F. Formability The state of the laminated metal plate obtained in the above E when deep drawing was performed on a two-piece can equivalent to 500 ml using the film side as the inner surface of the can body was observed. The evaluation was XX for peeling, rupture or whitening that was visually observed, but was not visually observed, but X where corrosion of the metal was observed by immersing in copper sulfate aqueous solution,腐 食 indicates that no corrosion was observed. G. FIG. Retort resistance The laminated metal plate obtained in the above E was treated at 125 ° C. for 30 minutes.
The state of the film after the min retort treatment was observed. The evaluation was evaluated as x with obvious whitening or white spots,
Although it is not clear, whitening that can be visually discerned was recognized as Δ, and that no change was visually observed was evaluated as ○. H. Impact resistance Ten laminated metal plates obtained in E above were
After retort treatment at 25 ° C for 30 minutes, and (b) 1
After retort treatment at 25 ° C for 30 minutes, storage in a 50 ° C atmosphere for one month,
50 kg weight (the tip is a spherical surface with a diameter of 1/2 inch)
The state of the film when dropped on a film surface from a height of cm was observed, and the impact resistance was evaluated according to the following criteria. ×: Peeling or breakage was visually observed even on one sheet. Δ: Three or more sheets were not visually observed, and metal corrosion was observed by immersion in an aqueous solution of copper sulfate. ○: Sulfuric acid was not visually observed. No more than 2 sheets were corroded when immersed in an aqueous copper solution. ：: Not visually observed.
No corrosion was observed on all the sheets. Using a 2P 500 ml can body obtained in F above, 500 g of distilled water was filled, and a commercially available 202-diameter aluminum EO lid was tightly sealed and sealed, and subjected to a retort treatment at 125 ° C. for 30 minutes. Was. Next, after sufficiently cooling to room temperature, the contents were tasted by 50 panelists to determine whether the smell, taste, etc. were different from distilled water, and the results were preserved according to the following criteria. It was used as an index of scent retention. ○: The number of people who sensed the difference between the two is less than 5. Δ: The number of persons who sense the difference between the two is 5 or more and less than 10. ×: 10 or more people sensed the difference between the two.

Example 1 55 parts by mass of polyester (A-1) and 45 parts of (B-1)
Parts by mass are dry-blended, melt-extruded into a sheet at 270 ° C. using an extruder equipped with a T-die (residence time is 5 minutes), and cooled by closely adhering to a cooling drum having a surface temperature of 18 ° C. An unstretched sheet having a thickness of 240 μm was obtained. After gripping the end portion of the obtained unstretched sheet with a clip of a tenter-type simultaneous biaxial stretching machine and running the preheating zone at 60 ° C.,
Simultaneous biaxial stretching was carried out at a temperature of 80 ° C. 3.0 times in MD and 3.3 times in TD. Thereafter, the TD was subjected to a heat treatment at a temperature of 150 ° C. for 4 seconds at a relaxation rate of 5%, cooled to room temperature and wound up to obtain a biaxially stretched film having a thickness of 25 μm.
Tables 1 and 2 show various characteristic values of the obtained film.

Examples 2 to 6 and Comparative Examples 1 to 8 Various films were obtained in the same manner as in Example 1 except that the kind of the starting resin, the compounding ratio and the film production conditions were changed as shown in Table 1. Was. Tables 1 and 2 show various characteristic values of the obtained film.

[0032]

[Table 1]

[0033]

[Table 2]

The films obtained in Examples 1 to 6 were excellent in heat laminating property, moldability, impact resistance, retort resistance, and flavor and fragrance retention, but were obtained in Comparative Examples 1 to 8. A film satisfying all the above-mentioned properties was not obtained.

[0035]

According to the present invention, it has excellent heat lamination properties and moldability, especially high-order workability such as drawing and ironing, and also has excellent impact resistance and retort resistance after molding. A polyester film for metal plate lamination suitable for coating a metal can can be provided.

[Brief description of the drawings]

FIG. 1 is an NMR chart of a film of the present invention.

FIG. 2 is an NMR chart in which a peak (Sab, Sba, Saa, Sbb) due to transesterification in FIG. 1 is enlarged.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Shigemi Majima 31-3 Uji Hinojiri, Uji City, Kyoto Prefecture Unitika F-term in the Uji Plastics Factory (reference) 3E033 AA06 BA07 BA17 BA18 BB08 CA20 FA01 4F071 AA45 AA46 AA80 AA83 AA84 AA87 AF01 AF23 AF58 AH05 BA01 BB06 BB08 BC01 BC02 4F100 AB01B AK41A AK42A AL05A BA02 EH17 EH172 EJ38 EJ382 GB16 JA04A JA12A JL01 YY00A 4J002 CF06X CF07W GG01

Claims (8)

[Claims] 1. A polybutylene terephthalate having a melting point of 200 to 223 ° C. or 80 to 40% by mass of a polyester (A) containing the same as a main component, and a polyethylene terephthalate having a melting point of 230 to 256 ° C. or a polyester (B) containing the same as a main component A) a polyester film for laminating a metal plate, which is a film comprising 20 to 60% by mass and having a transesterification index of 7 or less. 2. The polyester film for metal plate lamination according to claim 1, wherein the polyester (A) is 70 to 55% by mass and the polyester (B) is 30 to 45% by mass. 3. The polyester (B) having a melting point of 246 to 2
The polyester film for metal plate lamination according to claim 1 or 2, wherein the temperature is 56 ° C. 4. The polyester (A) having a residual index of 40 to 40.
The polyester film for metal plate lamination according to any one of claims 1 to 3, which is 75%. 5. The polyester film for laminating a metal plate according to claim 1, wherein the temperature-rise crystallization peak temperature from the amorphous state is in the range of 60 to 100 ° C. 6. The specific heat capacity at 60 to 100 ° C. is 0 J / g.
The polyester film for laminating a metal plate according to any one of claims 1 to 5, wherein the temperature is not lower than ° C. 7. A film-laminated metal plate obtained by laminating the polyester film for metal plate lamination according to claim 1 on a metal plate directly or via an adhesive. 8. A metal container molded using the film-laminated metal plate according to claim 7.