A method for manufacturing laminated metal sheets for packaging and a laminated metal sheet for packaging manufactured thereby.

Abstract

The present invention relates to a method for manufacturing laminated metal sheets for packaging and to laminated metal sheets for packaging manufactured thereby. The present invention also relates to the use of laminated metal sheets manufactured by the method according to the present invention for manufacturing seamless container bodies by drawing from the laminated metal sheets.

Description

[Technical Field]

[0001] The present invention relates to a method for producing a laminated metal sheet in a continuous coating line, wherein at least one side of the metal sheet has a laminate layer comprising at least an adhesive layer (A) and a bulk layer (B). The present invention also relates to a laminated metal sheet for packaging and a laminated metal sheet for packaging produced by the above method. [Background technology]

[0002] Laminated metal sheets for packaging include a metal sheet and a laminate layer covering at least one side of the metal sheet. Such laminated metal sheets are manufactured by laminating a laminate layer to one or both sides of a metal sheet. The laminate layer may consist of a single polymer layer or two or more individual coating layers stacked on top of each other. The laminate layers may be identical in composition, thickness, or buildup, or they may differ. Furthermore, the laminate layers on both sides of the metal sheet may differ in composition, thickness, or buildup. The laminate layer is usually supplied in the form of a thin film with a typical thickness of 10 to 50 μm.

[0003] If the laminate layer contains at least partially polyester, the laminate layer is applied to the metal sheet by (i) heat bonding the laminate layer to the metal sheet, (ii) using an adhesion promoter between the laminate layer and the metal sheet, (iii) using a laminate layer that includes an adhesive layer, or (iv) a suitable combination thereof. The laminate layer may be manufactured in-line and laminated to the metal sheet in an integrated lamination step, or a pre-manufactured laminate layer may be laminated to the metal sheet in a separate lamination step.

[0004] Before laminating the laminate layer to the metal sheet, the manufacturing method of the laminate layer, if not all, means that a thick cast film is stretched into a thin laminate layer, often by an annealing ("heat setting") stage, in order to avoid shrinkage of the laminate layer during lamination to the metal sheet. In most stretched laminate layers, the polymer is either biaxially or uniaxially oriented, depending on whether the film was biaxially or uniaxially stretched during its manufacture.

[0005] The most commonly used laminate layers are biaxially stretched (or biaxially oriented (BO)), in which case the laminate layer has substantially the same degree of orientation in a first direction and in a direction perpendicular to the first direction. The BO laminate layer is stretched to substantially the same degree in the mechanical direction (MD) and the transverse direction (TD). Examples of BO laminate layers based on semicrystalline polyesters such as polyethylene terephthalate (PET) and polybutylene terephthalate (PBT) and mixtures thereof, laminated to steel substrates, are disclosed in EP0312304.

[0006] An alternative type of lamination stretching is uniaxial stretching, as disclosed in US9346254. A mechanically oriented (MDO) lamination layer is provided on one or both sides of a metal substrate. Without heat setting, this uniaxial stretching produces a lamination layer that retains a strong orientation of polymer chains in the stretching direction. The lamination layer may also be uniaxially stretched transversely (TDO), which results in a strong orientation of polymer chains in the transverse direction. In both MDO and TDO lamination layers, the properties of the lamination layer differ in both in-plane directions (MD and TD).

[0007] The thermal adhesion of the laminate layer to the heated metal sheet reduces or eliminates residual orientation through remelting of the laminate layer, at least at the surface of the metal substrate. Usually, the laminated metal sheet is subjected to a heat treatment generally referred to as "post - heat", and the post - heat set - point temperature exceeds the melting point of the polymer within the laminate layer having the highest melting point. After the post - heat step, the laminated metal sheet is rapidly cooled, for example, by quenching the laminated metal sheet in a water tank or by using a water spray or mist or a combination thereof. The lamination step is usually carried out on a metal sheet or a metal strip, and it should be noted that the latter is usually supplied in a coil form enabling a continuous lamination process. In the context of the present invention, a metal strip, even if very long, shall also be regarded as a metal sheet.

[0008] The laminated metal sheet is often used for the manufacture of deep - drawn can bodies and for the manufacture of DWI (Drawn and Wall Ironed) can bodies or can ends. During these forming processes, the laminated metal sheet is subjected to quite extreme deformations. Also, the can body or can end can be subjected to subsequent heat treatment after formation, for example, during varnish curing or printing operations. This can cause problems such as the formation of micro - cracks (crazing), loss of polymer coating adhesion (in the case of can bodies and can ends), adhesion problems of the laminate layer to the metal sheet, insufficient barrier properties or poor corrosion resistance, or in the case of the end, problems during the process of opening the can (coating feathering). SUMMARY OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION

[0009] An object of the present invention is to provide a laminated metal sheet having good barrier properties, good corrosion resistance, and good adhesion of the laminate layer to the metal sheet.

[0010] Another object of the present invention is to provide a method for manufacturing a laminated metal sheet having good barrier properties and good corrosion resistance, as well as good adhesion of the laminate layer to the metal sheet.

[0011] Another object of the present invention is to provide a method for controlling the quality of a process for manufacturing a laminated metal sheet having good barrier properties and good corrosion resistance, as well as good adhesion of the laminate layer to the metal sheet.

Means for Solving the Problems

[0012] In a first aspect of the present invention, the above object is A method for manufacturing a laminated metal sheet (9) in a continuous coating line operated at a line speed v, comprising: The laminated metal sheet (9) includes a laminate layer (3), The method comprises the following steps: (a) Preparing a metal sheet (1); (b) Preparing a mainly or completely uniaxially oriented laminate layer (3) for coating at least one side of the metal sheet, where the laminate layer (3) includes at least an adhesive layer (A) and a bulk layer (B), and may optionally include one or more additional top layers (TL) on the bulk layer, The adhesive layer (A) is intended to adhere to the metal sheet and contains or comprises (i) a copolyester having 5 to 30% by weight of ethylene-isophthalate units, 70 to 95% by weight of ethylene-terephthalate units, and 0 to 5% by weight of other components, or (ii) 60 to 100% by weight of a non-crystallisable copolyester, 0 to 40% by weight of a crystallisable polyester or copolyester or a mixture thereof, such as polyethylene terephthalate, and 0 to 10% by weight of other components. The bulk layer (B) and the optional one or more additional top layers (TL) on the bulk layer essentially consist of poly(ethylene terephthalate) having at least 90% ethylene terephthalate units. The adhesive layer (A), the bulk layer (B), and the optional one or more additional top layers (TL) on the bulk layer may each optionally contain additives such as slip additives and anti-block particles. The bulk layer may optionally contain colorants, dyes, toners, or pigment particles; (c) Preheating the metal sheet (1) to a preheating setpoint temperature T1, where T1 is high enough to provide initial adhesion to the laminate layer (3), but not high enough to melt either the bulk layer (B) or the optional additional top layer (TL) within the laminate layer (3); (d) Laminating the laminate layer (3) onto the metal sheet (1) to produce a laminated metal sheet (9); (e) A step of postheating the laminated metal sheet (9) to a postheating setpoint temperature T2, where T2 is the temperature after the postheated laminated metal sheet (9) has cooled, in the range of 0 to 0.10. adh High enough to yield a value; (f) The heated laminated metal sheet (9) is cooled, preferably to ambient temperature, and the Euclidean distance matrix D of the adhesive layer (A) between the first ATR FTIR spectrum and the second ATR FTIR spectrum of the adhesive layer (A) is obtained. adh The value of has a value in the range of 0 to 0.10, and the Euclidean distance matrix D of the bulk layer (B) between the first ATR FTIR spectrum and the second ATR FTIR spectrum of the bulk layer (B) bulkA step of manufacturing a laminated metal sheet (9) having a value in the range of 0.10 or greater, Here, the first ATR-FTIR spectrum is measured using an ATR-FTIR spectrometer with an incident IR beam in a first in-plane direction relative to the mechanical direction of the laminated metal sheet or the corresponding free-standing laminate layer. The second ATR-FTIR spectrum is measured using the ATR-FTIR spectrometer after rotating the laminated metal sheet or the corresponding self-supporting laminate layer to a second in-plane direction at an angle α selected in the range of 70° to 110° within the plane of the laminate layer (3). The first and second ATR-FTIR spectra are from 1160 to 1520 cm⁻¹. -1 It is measured within a spectral range that includes the range; The method including This is achieved by [method].

[0013] In this method, a laminate layer that is mainly or completely uniaxially oriented is laminated to at least one side of a metal sheet in a continuous process, the laminate layer comprising at least an adhesive layer (A) and a bulk layer (B), and optionally comprising one or more additional top layers (TL) on the bulk layer, each layer containing 50% by mass or more polyester. The additional top layers may comprise one or more layers, which may be substantially identical in composition and / or thickness to the bulk layer (B), or they may be identical in polymer composition, but one of them may contain an additive. For example, the additional top layers may contain a slip additive and antiblocking particles, and the bulk layer may contain a colorant, dye, toner, or pigment particles. The adhesive layer (A) is intended to adhere to a metal sheet and contains or comprises a copolyester having 5-30% by weight of ethylene-isophthalate units, 70-95% by weight of ethylene-terephthalate units, and 0-5% by weight of other components, or the adhesive layer (A) contains or comprises 60-100% by weight of amorphous copolyester, 0-40% by weight of crystalline polyester or copolyester or a mixture thereof, e.g., polyethylene-terephthalate, and 0-10% by weight of other components. The bulk layer (B) and any optional additional top layer (TL) essentially consist of poly(ethylene terephthalate) having at least 90% by weight of ethylene-terephthalate units. The adhesive layer and the bulk layer may optionally contain additives such as slip additives and antiblocking particles, and the bulk layer may optionally contain additives such as colorants, dyes, toners, or pigment particles. Preferably, the amount of additives in each of the adhesive layer and / or bulk layer is a maximum of 5% by weight, with the exception of colorants, which may be present in the bulk layer at a maximum of about 20% by weight.

[0014] In the context of this invention, a method or product “including” certain features should be interpreted as meaning that it includes those features, but does not exclude the presence of other features, unless they make the claims unfeasible. Where the expression “consists of” is used, no further features other than those following the expression are present in the apparatus / method / product.

[0015] To improve the adhesion of the laminate layer to the metal sheet, it is important that the adhesive layer has sufficient initial adhesion to the metal sheet, as the adhesion has not yet reached its maximum value at this stage during the continuation of the lamination process. This initial adhesion is achieved by preheating the metal sheet to a preheating setpoint T1 that is high enough to provide initial adhesion to the laminate layer. For this reason, T1 must be above the glass transition temperature (Tg) of the polymer material in the adhesive layer. In order to preserve the desirable properties of the bulk layer in the pre-lamination stage, particularly the orientation of the polymer layer (MDO or TDO), it is important that T1 does not exceed the melting temperature of the bulk layer during the pre-lamination stage and during lamination, so that the bulk layer retains almost, if not all, of the orientation of the bulk layer that it had before the pre-lamination step. In the post-lamination stage, the laminated metal sheet is heated to a post-heating setpoint T2 that is high enough to melt or soften the adhesive layer without melting the bulk layer within the laminate layer, but sufficient to release the stress between the amorphous adhesive layer (A) and the laminate layer (B) which remains mainly or completely uniaxially oriented after cooling. After the post-heated laminated metal sheet is cooled, preferably to ambient temperature, the molten adhesive layer solidifies and, as a result of its composition, remains completely or mostly amorphous, thereby achieving good adhesion properties of the adhesive layer to the metal sheet. Therefore, the cooling rate must be fast enough to prevent crystallization of the adhesive layer. For some adhesive layers, such as PETg (polyethylene terephthalate glycol modified) adhesive layers that cannot crystallize, the cooling rate is not critical, but from the viewpoint of production consistency, it is preferable to use rapid cooling by air, mist or water spray, or quenching in a water bath. Rapid cooling does not affect PETg, which is non-crystallizable, but it suppresses crystallization of the adhesive layer of other types, such as i-PET CA248 (see Table 1). Experimental evidence clearly shows that post-heating to the T2 setpoint is essential.Without post-heating, on the one hand, the adhesion between the adhesive layer and the metal sheet is insufficient, and on the other hand, stress is generated between the amorphous adhesive layer (A) and the uniaxially oriented bulk layer (B) due to the different volume relaxation rates of the amorphous adhesive layer and the uniaxially oriented bulk layer (B), resulting in unsatisfactory subsequent properties of the laminated metal sheet after quenching. T2 must be high enough to achieve melting or at least softening of the adhesive layer. The bulk layer does not need to be melted, i.e., T2 remains below the melting temperature of the bulk layer polymer, so this layer retains almost all, if not all, of its previously existing orientation. This also preserves the bulk properties, resulting in sufficient adhesion of the laminate layer to the metal sheet while the bulk layer has good barrier and corrosion resistance.

[0016] The degree of orientation of the adhesive layer and bulk layer can be measured by determining the ATR-FTIR spectra in two directions recorded outside the corresponding layer, as described in International Publication No. 2021180651. This specification specifies a particular frequency range measured in two different directions of a laminated metal sheet sample rotated at a set angle α with respect to the normal of the laminated metal sheet sample (the specific frequency range is 1160–1520 cm⁻¹). -1The orientation of a laminate layer or the orientation of individual layers within a laminate layer laminated to a metal sheet can be determined by comparing two ATR-FTIR spectra (which include, but are not necessarily, a range of). Preferably, the first spectrum is measured in the direction of the machine, and the second spectrum is measured after rotating the sample at an angle selected in the range of 70–110°. Alternatively, the first spectrum is measured in a direction perpendicular to the machine, and the second spectrum is measured after rotating at an angle selected in the range of 70–110°. The rotation angle α between the two directions of the sample is preferably 85°–95°, more preferably about 90°. An advantage of such a method of predicting residual orientation based on measuring two ATR-FTIR spectra is that it can be implemented in a wide range of mixtures such as PET-based and / or PBT-based polyesters, copolyesters, and mixtures thereof.

[0017] According to the IDENT user manual for Opus spectroscopy software (version 6) by Bruker, the comparison of two spectra (A and B) results in a spectral distance D. The better the two spectra match, the smaller the spectral distance. Two spectra with a spectral distance of 0 are completely identical (in the tested frequency range). The greater the difference between the two spectra, the greater the spectral distance.

[0018] The spectral distance can be presented in the form of a value D. Different methods can be employed to calculate the value of the spectral distance D. One of these methods is the standard algorithm, which uses the Euclidean distance to determine the spectral distance. This Euclidean distance is,

number

[0019] Before this calculation, the spectrum must be preprocessed by vector normalization. The mean y-value of the spectrum is calculated and subtracted from the spectrum, thereby centering the spectrum around y=0. This is followed by calculating the sum of the squares of all y-values, and each spectrum is divided by the square root of this sum. The resulting spectrum's vector norm is 1.

[0020]

number

[0021] If a vector-normalized spectrum is represented in n-dimensional space, where n is the number of selected data points, then all spectra lie on the unit sphere (an n-dimensional sphere around the coordinate origin with radius 1). The maximum distance between two spectra is the diameter of the unit sphere, i.e., D=2. The minimum distance is when all points in the two spectra overlap on the unit sphere, i.e., D=0.

[0022] The comparison of two ATR-FTIR spectra is performed using the Euclidean distance D, which is a measure of the degree to which the two ATR-FTIR spectra deviate. The inventors have developed a method for determining D for adhesive layers. adh While the target value for the bulk layer must be within the range of 0 to 0.10, D bulk We discovered that the target value must be at least 0.10.

[0023] The machine direction (MD) of the laminated metal sheet is the same as the rolling direction (RD) of the metal sheet and is also the same as the moving direction of the metal sheet in the lamination process. The present invention is particularly applicable when the laminate layer is subsequently stretched only in the machine direction (MDO) or only in the transverse direction (TDO).

[0024] A D value of zero means that the first and second spectra coincide in the observed range region and that there is no difference in the orientation within the corresponding layers of the laminate layer in two directions. A value of D>0 indicates the presence of a residual orientation in the corresponding part of the laminate layer, and a higher D value indicates a greater difference between the two spectra, which means that the orientation of the polymer chains of the laminate layer is more different in two directions.

[0025] In one embodiment, the target value of D bulk is at least 0.15, preferably at least 0.20, more preferably at least 0.30, and even more preferably at least 0.40.

[0026] In one embodiment, the target value of D adh is at most 0.08, preferably at most 0.06, more preferably at most 0.04, and even more preferably at most 0.03. The preferred minimum value of D adh is 0.01.

[0027] In a preferred embodiment, the ratio of D bulk / D adh is at least 1.50, preferably at least 5.00, more preferably at least 7.00, even more preferably at least 10.00, and even more preferably at least 12.50.

[0028] The present invention is applicable when the laminate layer before lamination onto a metal sheet has a distinct difference in orientation in the rolling direction and the transverse (TD) direction. This applies when the laminate layer before lamination is completely or mainly stretched in a machine-directed orientation (MDO laminate layer) or completely or mainly stretched in the transverse direction (TDO laminate layer). If the orientation in both directions (MD and TD) is the same before lamination, D adh and D bulk The risk is likely to be low before lamination. This applies to biaxially oriented laminate layers stretched to the same or substantially the same extent in MD and TD, as well as to extruded laminate layers that are laminated directly onto metal after extrusion without intermediate solidification and post-solidification stretching. The present invention does not apply to ordinary BO laminate layers where the amount of stretching in both of the two orthogonal directions is the same, or to extruded laminate layers that are laminated directly onto metal after extrusion without intermediate solidification and post-solidification stretching. Laminate layers that are stretched in two orthogonal directions but where the amount of stretching in one direction is significantly different are not considered biaxially oriented in the context of the present invention, and these are considered primarily uniaxially oriented laminate layers.

[0029] The method for preheating the metal strip in the first heating device (2) is not particularly limited and may include passing the strip through a heating roll, conductive heating, induction heating, radiant heating, etc. The method for postheating the laminated metal sheet in the second heating device (6) is preferably a non-contact method such as heating in a high-temperature gas environment or induction heating. The method for cooling in the quenching device (7) is not particularly limited and may include applying cold air, water spray, mist, or passing through a chilled water bath.

[0030] Preferred embodiments of the method of the present invention are provided by dependent claims 2 to 11.

[0031] In one embodiment, the first in-plane incident IR beam is parallel or perpendicular to the mechanical direction of the laminated metal sheet or the corresponding self-supporting laminate layer.

[0032] In one embodiment, an incident IR beam in a first in-plane direction of a laminated metal sheet is measured, and after rotating the laminated metal sheet or a sample of the corresponding self-supporting laminate layer by an angle α to a second in-plane direction selected in the range of 85° to 95° within the plane of the laminate layer, a second ATR FTIR spectrum is measured, where the angle α is preferably about 90°.

[0033] In one embodiment, the adhesive layer contains (i) a copolyester having 3.5 to 12.5% ​​by weight of ethylene-isophthalate units, preferably 4.0 to 11.0% by weight of ethylene-isophthalate units, or (ii) a copolyester having 60 to 100% by weight of amorphous copolyester, preferably 80 to 100% by weight of amorphous copolyester.

[0034] In one embodiment, the laminate layer also includes an additional top layer (TL) on top of the bulk layer (B), the additional top layer (TL) may contain one or more individual layers. The additional top layer may be substantially identical to the bulk layer (B) in composition and / or thickness, or they may be identical in polymer composition, but one of them may contain additives, such as an additional top layer containing slip additives and antiblocking particles, and the bulk layer may contain colorants, dyes, toners, or pigment particles.

[0035] In a preferred embodiment, the laminate layer for coating at least one side of the metal sheet comprises two or more layers. • Melting thermoplastic polymer granules in one or more extruders. - A laminate layer consisting of two or more layers is formed by passing one or more molten polymers through an extrusion die and / or two or more calender rolls. Next, optionally, • Cooling the laminate layer to form a solid laminate layer. Optionally, trim the edges of the solid laminate layer. - Reducing the thickness of the solid laminate layer by stretching it in a stretching device by applying stretching force only in the longitudinal direction or only in the transverse direction. Optionally, trim the edges of the stretched solid laminate layer. Provided by [company name].

[0036] The reduction in the thickness of the solid laminate layer as a result of stretching is at least 50%, preferably at least 60%, and more preferably at least 65%. The degree of orientation of the laminate layer is directly related to the amount of reduction. The greater the amount of reduction, the higher the degree of orientation as a result of the orientation of polymer chains within the laminate layer. A higher degree of uniaxial orientation of the laminate layer is associated with a higher ratio of D bulk / D adh This is considered beneficial to the method according to the present invention because it makes it possible to reach [the desired state].

[0037] Extrusion of multilayer laminates can be carried out by extruding individual polymer layers from multiple individual flat extrusion dies, or by extruding multiple individual polymer layers from a co-extrusion die.

[0038] In one embodiment, the laminate layer (3) is laminated onto a metal sheet to produce a laminated metal sheet without interruption in an inline and continuous process. This means that the production of the laminate layer is carried out immediately before the lamination process without intermediate cutting, coil winding, and unwinding of the laminate layer, and instead it is applied to the metal sheet without interruption of individual processing steps.

[0039] In one embodiment, the method according to the present invention provides a Euclidean distance D after post-heating and cooling. adhIf the value exceeds the target value, and / or after heating and cooling, bulk If the value falls below the target value, it is used to adjust the process parameters of the continuous coating line, such as one or more of the preheating setpoint (T1), the required postheating setpoint (T2), and the line speed (v) of the continuous coating line. If the postheating setpoint (T2) is not applied, or if it is applied, D adh If it is greater than the corresponding threshold, D bulk If the value is smaller than the corresponding threshold, the adhesion of the laminate layer and the degree of orientation of the laminate layer are insufficient, and the product is likely to fall below standards. This can lead to the rejection of the material or a downgrade to a lower-value product.

[0040] In one embodiment, the metal sheet is a steel sheet, preferably, the steel is uncoated cold-rolled steel, black plate, tinplate (i.e., steel coated with a thin layer of tin, typically intended for packaging applications), ECCS (also known as TFS), TCCT® (a registered trademark of Tata Steel), galvanized steel, or aluminum-plated steel. In another embodiment, the metal sheet is an aluminum or aluminum alloy sheet. The metal sheet is preferably supplied in coil form, and its thickness is typically 0.15 to 0.40 mm. Laminated metal sheets are also preferably supplied in coil form, but they may also be supplied to customers in the form of cut-to-length metal sheets or blanks.

[0041] D of the laminate layer of a laminated metal sheet obtained by lamination of (mainly) uniaxially oriented polyester films bulk The method for determining this is as follows: (a) Step of obtaining a sample of laminated metal sheet; (b) The step of placing the laminated metal sheet sample in the ATR detector of the ATR-FTIR spectrometer such that the rolling direction of the laminated metal sheet is parallel to the plane of incidence of infrared light from the spectrometer's infrared light source to the ATR crystal; (c) at least frequency range 1160-1520 cm -1 A step to record a reflectance profile over time; (d) A step of generating a first ATR-FTIR spectrum of the sample in this frequency range using the Fourier transform; (e) A step of generating a second ATR-FTIR spectrum by rotating the laminated metal sheet sample by an angle α selected in the range of 70° to 110° in a plane perpendicular to the normal of the sample surface, and repeating steps c and d; (f) Euclidean distance D between the two spectra bulk By calculating the spectral distance represented by , we can determine at least 1160–1520 cm⁻¹ -1 A step of mathematically comparing the correlation between the first spectrum and the second spectrum in the frequency range; Includes.

[0042] D of the laminate layer of the laminated metal sheet adh The method for determining this involves the following steps between steps a and b: A self-supporting laminate layer is obtained by decomposing the metal sheet from the laminated metal sheet, and steps b to f are repeated with respect to the metal-facing surface of the self-supporting laminate layer. It also includes.

[0043] The laminated metal sheet according to the present invention may have a laminate layer on one or both sides of the metal sheet. In the latter case, the laminate layers (3a, 3b in Figure 1) may be the same or different in terms of composition, thickness, or build-up.

[0044] The method for preheating a metal strip before laminating a laminate layer onto it is not particularly limited and may include passing the strip through a heating roll, conductive heating, induction heating, radiant heating, etc. The method for postheating the laminated metal sheet is preferably a non-contact method such as heating in a high-temperature gas environment or induction heating. In a preferred embodiment, postheating of the laminated metal sheet to a preheating setpoint T1 and / or postheating setpoint T2 is carried out using induction heating. By induction heating, the metal sheet is heated, thereby preventing the outer polymer layer from becoming too hot, and thereby preventing the melting of the bulk layer (B) or any other additional layer (TL) on top of the bulk layer.

[0045] According to a second aspect, the present invention also relates to a laminated metal sheet (9) for packaging that can be obtained or obtained by a method according to the present invention, The laminated metal sheet comprises a metal sheet (1) and a laminate layer (3) covering at least one side of the metal sheet. The laminate layer (3) includes an adhesive layer (A) and a bulk layer (B), The adhesive layer is bonded to the metal sheet and contains or contains a copolyester having 5-30% ethylene isophthalate units, 80-95% ethylene terephthalate units, and 0-5% other units. The bulk layer essentially consists of poly(ethylene terephthalate) having at least 90% ethylene terephthalate units. The adhesive layer (A) and the bulk layer (B) may each optionally contain additives such as slip additives and antiblocking particles. The bulk layer (B) may optionally further contain colorants, dyes, toners, or pigment particles. In the laminated metal sheet, the Euclidean distance matrix D of the adhesive layer (A) between the first ATR FTIR spectrum and the second ATR FTIR spectrum of the adhesive layer (A) adhThe value of has a value in the range of 0 to 0.10, and the Euclidean distance matrix D of the bulk layer (B) between the first ATR FTIR spectrum and the second ATR FTIR spectrum of the bulk layer (B) bulk The value of has a range of 0.10 or greater. The first ATR-FTIR spectrum is measured using an ATR-FTIR spectrometer with an incident IR beam in a first in-plane direction relative to the mechanical direction of the laminated metal sheet or the corresponding self-supporting laminate layer. The second ATR FTIR spectrum is measured using the ATR FTIR spectrometer after rotating the laminated metal sheet or the corresponding self-supporting laminate layer to a second in-plane direction at an angle α selected in the range of 70° to 110° within the plane of the laminate layer. The first and second ATR-FTIR spectra are from 1160 to 1520 cm⁻¹. -1 Measured within a spectral range that includes the range, D bulk / D adh This is embodied in the laminated metal sheet (9), preferably having a ratio of at least 1.50.

[0046] In one embodiment, D bulk / D adh The ratio is at least 1.50. The higher this ratio, the better the overall performance of the laminated metal sheet.

[0047] The recrystallization fraction of the bulk layer within the laminate layer is preferably at least 20% by weight, preferably at least 25% by weight, and more preferably at least 30%. This ensures that desirable bulk layer properties, good barrier properties, and corrosion resistance are maintained at a sufficiently high level. A larger recrystallization fraction is better for maintaining bulk layer properties.

[0048] In one embodiment, the laminate layer is oriented primarily or entirely towards the machine direction, or primarily or entirely perpendicular to the machine direction, as a result of stretching during the manufacture of the laminate layer by applying stretching force only in the longitudinal direction or only in the transverse direction within the stretching apparatus, and the reduction in the thickness of the solid laminate layer as a result of stretching is at least 50%, more preferably at least 60%, and even more preferably at least 65%.

[0049] According to a third aspect, the present invention is also embodied in a can body, can end, or can lid manufactured from a laminated metal sheet according to the present invention.

[0050] The present invention is a process for manufacturing a seamless container body from a laminated metal sheet manufactured according to the present invention, characterized in that a cup having end walls and side walls rising from the periphery of the end walls is formed from the laminated metal sheet, wherein at least one side of the cup is covered with the laminate layer, preferably both sides of the cup are covered with the laminate layer. In the case of a lid or can body, preferably at least the inside of the cup is covered with the laminate layer.

[0051] The present invention is also embodied in a process for manufacturing a seamless container body from a laminated metal sheet, comprising: drawing a cup having end walls and side walls rising from the periphery of the end walls from the laminated metal sheet; and optionally, performing an additional step of redrawing the cup to reduce the diameter of the cup and increase the height of the walls in order to form a can body; the can body may also be subjected to wall ironing.

[0052] In one embodiment, a laminated metal sheet (9), The adhesive layer (A) contains or comprises (i) 5 to 15% by weight of ethylene isophthalate units, 80 to 95% by weight of ethylene terephthalate units, and 0 to 5% by weight of other components, or (ii) contains or comprises 60 to 100% by weight of amorphous copolyester, 0 to 40% by weight of crystalline polyester or copolyester or a mixture thereof, for example, polyethylene terephthalate, and 0 to 10% by weight of other components. The main polymer resin used in one or more additional top layers is poly(ethylene terephthalate) having at least 90% ethylene terephthalate units. The adhesive layer (A) and the bulk layer (B) may each optionally contain additives such as slip additives and antiblocking particles. A laminated metal sheet (9) is provided, wherein the bulk layer (B) may optionally further contain colorants, dyes, toners, or pigment particles.

[0053] The present invention is also embodied in a process for producing can ends or can lids from laminated metal sheets manufactured according to the present invention by known means. [Examples]

[0054] To illustrate the present invention, a laminated metal sheet was manufactured. In all cases, both sides of the metal sheet are provided with a thermoplastic polymer laminate layer. The metal sheet is a low-carbon cold-rolled packaging steel commonly known as "ECCS" (Electrolytically Chromium Coated Steel), which is electrolytically coated on both sides with metallic chromium and chromium oxide layers, with a total chromium content of approximately 90 mg / m² on each side. 2 The metal sheet is provided as a coiled metal strip.

[0055] Comparative and test samples were prepared according to the present invention using the laminate layers shown in Table 1. The laminate layers shown in Table 1 were prepared by casting polymer films using different laminate layer compositions and uniaxially stretching them in the mechanical direction (MDO) at a stretch ratio of 1:4. The total thickness of the laminate layer was 20 μm, of which the thickness of the adhesive layer (A) was 4 μm, the thickness of the bulk layer (B) was 12 μm, and the thickness of the additional top layer (TL) was 4 μm.

[0056] [Table 1]

[0057] A laminate layer was laminated to a metal sheet by a thermal bonding process schematically shown in Figure 1. The metal strip or sheet (1) is passed through a first heating device (2), where the temperature of the metal strip is raised to a preheating setpoint T1 suitable for lamination. The coils of the laminate layer films (3a, 3b) are simultaneously unwound and passed together with the preheated metal strip or sheet through a pair of laminating rollers (4a, 4b). It is clear that this process is also applicable when only one side of the metal sheet is coated. The resulting laminated metal strip or sheet (5) is passed through a second heating device (6), where the temperature of the laminated strip is raised to a postheating setpoint T2, for example using induction heating. After the second heating device, the laminated metal sheet is immediately cooled by passing through a quenching device (7) to reach ambient temperature (usually room temperature). The method for preheating the metal strip in the first heating device is not particularly limited and may include passing the strip through a heating roll, conductive heating, induction heating, radiant heating, etc. The method for postheating the laminated metal sheet in the second heating device is preferably a non-contact method such as heating in a high-temperature gas environment or induction heating. The method for immediate cooling in the quenching device is not particularly limited and may include applying cold air, water spray, mist, or passing through a chilled water bath. The laminated metal sheet is then passed through drying rollers (8a, 8b), after which a sample may be collected for obtaining an ATR-FTIR profile of the laminated metal sheet and the corresponding self-supporting laminate layer sample. In a typical manufacturing process, the laminated metal sheet is usually coiled for delivery to the customer after passing through drying rollers (not shown).

[0058] Table 2 shows the comparative sample ("CS") and the inventive sample ("TS"). Table 2 also shows the corresponding process conditions used to obtain these samples.

[0059] For flat samples, it is arbitrary which side is the outside and which is the opposite. When applied to a can, the outside represents the outside of the can, and the opposite side is the inside where the can contacts its contents. After sample preparation, the ATR-FTIR spectrum on the laminated metal sheet is recorded, and the spectral distance D bulk The value was determined. D adh To determine this, it was necessary to analyze the self-supporting laminate layer. A sample of laminated metal sheet from the line was immersed in an 18% hydrochloric acid aqueous solution to dissolve the metal sheet, thereby obtaining the self-supporting laminate layer.

[0060] [Table 2]

[0061] A laminated metal sheet sample was cut into 5.0 × 5.0 cm panels. ATR-FTIR spectra were recorded using a Bruker Tensor II ATR-FTIR spectrometer with a diamond crystal at a fixed incidence angle of 45°. 0.4 cm -1 Resolution: 1160-1520cm -1 The ATR-FTIR signal was recorded using 16 scans. The background signal was recorded before recording the actual ATR-FTIR spectrum.

[0062] Two spectra were recorded for each sample. The first spectrum was recorded using a laminated metal sheet sample or a self-supporting laminate layer on the metal-facing side in the rolling direction perpendicular to the plane of incidence of infrared light from the spectrometer infrared light source onto the ATR crystal (which is the same as the machine direction (MD) of the continuous coating line). The second spectrum was recorded after rotating the laminated metal sheet sample or the self-supporting laminate layer on the metal-facing side by 90° in the plane of the sample.

[0063] A mathematical comparison of the first and second spectra corresponding to the adhesive layer (A) and bulk layer (B) is performed from 1160 to 1520 cm⁻¹.-1 This was achieved by calculating the spectral distance value D after vector normalization (to compensate for differences in intensity due to surface defects) within the spectral range. Calculated spectral distance value D bulk and D adh D is the Euclidean distance between two corresponding spectra. The calculated Euclidean distance can range from 0 (perfect spectral match) to 2 (perfect spectral mismatch). By comparing the results of known good and bad samples, D can be used as a threshold. bulk , D adh = 0.10 was determined. The mathematical background is well known to those skilled in the art, and an outline thereof can be found in International Publication No. 2021 / 180651A1, page 11, lines 11-38, which is incorporated herein by reference.

[0064] Thermal properties of the laminate layer (T g , T m The bulk crystallinity was determined by DSC. Spectra were recorded using a Mettler Toledo DSC821e instrument operated at a heating rate of 10°C / min. For DSC, it was necessary to analyze the self-supporting film obtained from the laminated metal sheet. A self-supporting laminate layer was obtained by dissolving the metal sheet by immersing a sample of the laminated metal sheet from the line in an 18% hydrochloric acid aqueous solution. After dissolving the metal sheet, the laminate layer was thoroughly washed and dried. The crystal fraction was determined from the heat of recrystallization and from the melting during the first heating run, which is described in detail elsewhere. The orientation-induced crystallinity value (weight %) was:

number

[0065] Adhesion performance to flat materials was evaluated using a 180-degree peel test in accordance with ISO 11339:2010. The test was performed using an Instron 5587 tensile testing machine equipped with pneumatic grips and operated at a crosshead speed of 25 mm / min, with 15 mm wide strips cut in the rolling direction from a wider laminate sheet. Prior to cutting, the initial point for the peel test was obtained on the sheet by etching off the edges of the laminated metal sheet in 18% hydrochloric acid to partially dissolve the steel base. The peel force was defined as the average of the first peak load values ​​expressed in N / 15 mm by testing five specimens. Some samples of the laminated metal sheet had a brittle laminate layer, and the laminate layer broke off before the first peak load value could be recorded. In this case, to confirm that the fracture of the laminate layer was due to high laminate layer adhesion rather than the brittleness of the laminate layer itself, the force at maximum load on the self-supporting laminate layer in the rolling direction was additionally evaluated. The force at maximum load, expressed in N / 15mm, is defined by the formula: F = d × w × σ, where d and w are the thickness and width of the laminate layer, respectively. In this example, the values ​​of d and w are 20 microns and 15 mm, respectively. σ is the tensile stress determined according to ISO 527. The tensile stress is defined as the average tensile stress at maximum load, expressed in MPa, by testing five specimens of 10 mm wide strips cut from the self-supporting laminate layer in the rolling direction.

[0066] The adhesion performance to deformed, dry (as manufactured) or wet (sterilized) materials was evaluated as follows. First, deformation was induced using the "Erichsen Cupping Test" described in ISO 20482:2013. In all cases, the cup height was 5 mm. For sterilization, a 7.5 × 15.0 cm deformed panel was immersed in an aqueous solution containing 12 g / L of commercially available Maggi® bouillon (dried broth powder or cubes) + 2 g / L of plasmal in a sealed container, then sterilized at 121°C for 90 minutes, and then the sample was cooled. The adhesion to the deformed samples in dry and wet states was then evaluated by applying the so-called "X-cut Pull-Off" method. In this method, the X-cut is applied to the deformed portion of the unsterilized and sterilized panel and the subsequent adhesive tape (3M Scotch Nr. 610) according to the method described in ASTM D3359. Subsequently, delamination was evaluated using a scale ranging from 0 (excellent) to 5 (poor) (Table 3). All tests were performed three times on each face of each variant of the laminated metal sheet shown in Table 2. The scores were then averaged across the three results and rounded to the nearest integer.

[0067] The susceptibility of deformed materials to cracking was evaluated. A cup height of 5 mm was used, and deformation was induced using the "Erichsen test" described in ISO 20482:2013. The presence of cracks at the tip of the cup was evaluated by acquiring optical images using an Olympus BX51M microscope equipped with a 20x or 50x objective lens. Optical images were acquired by focusing on the outer layer of the polymer coating. The level of cracking was evaluated as "none," "small," or "severe" (Table 4).

[0068] [Table 3]

[0069] [Table 4]

[0070] All characterization data for the test samples and comparison samples are summarized in Table 5. Characterization data for the self-supporting laminate layer and adhesion and sterilization data for the laminated metal sheet samples are then calculated using spectral distance values ​​D. bulk and D adh , and ratio D bulk / D adh It is compared to the value of D. bulk and D adh The values ​​were derived by comparing the first and second ATR-FTIR spectra determined for the corresponding laminated metal sheet or self-supporting laminate layer.

[0071] These results clearly show that applying the laminate layer to a metal sheet without post-heating according to the present invention results in a poorly performing laminated metal sheet (CS1 / CS6 / CS10). bulk / D adh The larger the ratio, the greater D bulk >0.10 and D adh It is clear from this table that better performance of laminated metal sheets is provided when the value is <0.10.

[0072] The present invention will be explained using the following non-limiting figures. [Brief explanation of the drawing]

[0073] [Figure 1] Figure 1 is a schematic diagram of an industrial continuous coating line. [Figure 2] Figure 2 is a schematic diagram of the distance between the two spectra. [Figure 3] Figure 3 shows the spectrum of a sample with high anisotropy. [Figure 4] Figure 4 shows the spectrum of an isotropic sample. [Figure 5] Figure 5 shows several embodiments of laminated metal sheets: a) metal sheet (1) with adhesive layer (A) and bulk layer (B) on one side of the metal sheet, b) metal sheet (1) with adhesive layer (A) and bulk layer (B) on both sides of the metal sheet, and c) metal sheet (1) with adhesive layer (A), bulk layer (B) and an additional top layer (TL) on only one side of the metal sheet. [Figure 6] Figure 6 shows a schematic explanation of the ATR-FTIR spectrum measurement. [Modes for carrying out the invention]

[0074] The laminate layer is laminated to the metal strip by the process schematically shown in Figure 1, as described above herein.

[0075] The spectral distance D is proportional to the area between the two curves. Figure 2 shows two model sinusoidal curves. The spectral distance is proportional to the gray area between the two sinusoidal curves. Figure 3 shows two curves of two different polymer layers that have a difference in ATR-FTIR response, indicating a significant difference in orientation between the two orthogonal directions in which the ATR-FTIR response was measured. Figure 4 shows two curves of two different polymer layers that have the same ATR-FTIR response (and therefore a very small D), indicating virtually no difference in orientation, suggesting random orientation of polymer chains or amorphous microstructure.

[0076] Figure 5 shows a schematic structure of a laminated metal sheet. The top figure shows the simplest form of a laminated metal sheet 9 having a metal sheet 1 provided with one laminate layer 3 consisting of an adhesive layer (A) and a bulk layer (B). Figure 5b shows the same laminate layers as in Figure 5a provided on both sides of the metal sheet 1. Figure 5c shows a more complex embodiment of the present invention, in which a multilayer laminate layer 3 is provided on the metal sheet 1, and the multilayer consists of three separate layers TL, B, and A, which (in this example) function as an additional top layer, bulk layer, and adhesive layer, respectively, each of which may have a different composition to suit the requirements imposed on the individual layer.

[0077] Figure 6 provides a schematic explanation of the preparation of a sample obtained from a laminated metal sheet and subsequent measurements using an ATR-FTIR spectrometer. The first spectrum is measured in the direction of the incident IR beam parallel to the machine direction (MD), which is identical to the rolling direction (RD). The second spectrum is measured in the direction of the incident IR beam approximately perpendicular to the machine direction (rotation angle α). The Euclidean distance D is measured between these two spectra.

[0078] [Table 5]

Claims

1. A method for manufacturing a laminated metal sheet (9) in a continuous coating line operated at line speed v, The laminated metal sheet (9) includes a laminate layer (3), The above method involves the following steps: (a) Step of preparing the metal sheet (1); (b) A step of preparing a laminate layer (3) which is mainly or completely uniaxially oriented for coating at least one side of the metal sheet, Here, the laminate layer (3) includes at least an adhesive layer (A) and a bulk layer (B), and may optionally include one or more additional top layers (TL) on the bulk layer. The adhesive layer (A) is intended to adhere to the metal sheet and contains or comprises (i) a copolyester having 5 to 30% by weight of ethylene isophthalate units, 70 to 95% by weight of ethylene terephthalate units, and 0 to 5% by weight of other components, or (ii) a copolyester containing or comprising 60 to 100% by weight of amorphous copolyester, 0 to 40% by weight of crystalline polyester or copolyester or a mixture thereof, for example, polyethylene terephthalate, and 0 to 10% by weight of other components. The bulk layer (B) and the optional one or more additional top layers (TL) on the bulk layer essentially consist of poly(ethylene terephthalate) having at least 90% ethylene terephthalate units. The adhesive layer (A), the bulk layer (B), and the optional one or more additional top layers (TL) on the bulk layer may each optionally contain additives such as slip additives and antiblocking particles. The bulk layer may optionally contain colorants, dyes, toners, or pigment particles; (c) Preheating the metal sheet (1) to a preheating setpoint temperature T1, where T1 is high enough to provide initial adhesion to the laminate layer (3), but not high enough to melt either the bulk layer (B) or the optional additional top layer (TL) within the laminate layer (3); (d) Laminating the laminate layer (3) onto the metal sheet (1) to produce a laminated metal sheet (9); (e) A step of postheating the laminated metal sheet (9) to a postheating setpoint temperature T2 without melting either the bulk layer (B) or the optional additional top layer (TL) within the laminate layer (3), where T2 is a temperature in the range of 0 to 0.10 after the postheated laminated metal sheet (9) has cooled. ａｄｈ High enough to yield a value; (f) The heated laminated metal sheet (9) is cooled, preferably to ambient temperature, and the Euclidean distance D of the adhesive layer (A) between the first ATR FTIR spectrum and the second ATR FTIR spectrum of the adhesive layer (A) is measured. ａｄｈ The value of is in the range of 0 to 0.10, and the Euclidean distance D of the bulk layer (B) between the first ATR FTIR spectrum and the second ATR FTIR spectrum of the bulk layer (B) is ｂｕｌｋ A step of manufacturing a laminated metal sheet (9) having a value in the range of 0.10 or more, Here, the first ATR-FTIR spectrum is measured using an ATR-FTIR spectrometer with an incident IR beam in a first in-plane direction relative to the mechanical direction of the laminated metal sheet or the corresponding self-supporting laminate layer. The second ATR-FTIR spectrum is measured using the ATR-FTIR spectrometer after rotating the laminated metal sheet or the corresponding self-supporting laminate layer to a second in-plane direction at an angle α selected in the range of 70° to 110° within the plane of the laminate layer (3). The first and second ATR-FTIR spectra are from 1160 to 1520 cm⁻¹. －１ It is measured within a spectral range that includes the range; The method, including the method described above.

2. The method according to claim 1, wherein the first in-plane incident IR beam is parallel or perpendicular to the mechanical direction of the laminated metal sheet or the corresponding self-supporting laminate layer.

3. The incident IR beam in the first in-plane direction of the laminated metal sheet or the corresponding self-supporting laminate layer is measured. The laminated metal sheet or the corresponding self-standing laminate layer is rotated by an angle α to a second in-plane direction selected within the range of 85° to 95° within the plane of the laminate layer, and then the second ATR FTIR spectrum is measured. The method according to claim 1 or 2, wherein the angle α is preferably 90°.

4. The method according to any one of claims 1 to 3, wherein the adhesive layer (A) contains or comprises a copolyester having 3.5 to 12.5% ​​by weight of ethylene-isophthalate units.

5. The method according to any one of claims 1 to 4, wherein the adhesive layer (A) contains or contains a copolyester having 4.0 to 11.0% by weight of ethylene-isophthalate units.

6. The method according to any one of claims 1 to 3, wherein the adhesive layer (S) contains or comprises 80 to 100% by weight of an amorphous copolyester, such as PETg.

7. D ｂｕｌｋ / D ａｄｈ The method according to any one of claims 1 to 6, wherein the target value is at least 1.

50.

8. The method according to any one of claims 1 to 7, wherein the laminate layer (3) also includes at least one or more additional top layers (TL) on the bulk layer (B).

9. The laminate layer (3) for coating at least one side of the metal sheet is - To produce one or more molten polymers having the composition necessary to produce the adhesive layer (A), bulk layer (B), and one or more optional additional top layers (TL) by melting thermoplastic polymer granules in one or more extruders. - The laminate layer (3) comprising two or more layers is formed by passing the one or more molten polymers through an extrusion die and / or two or more calender rolls. Next, optionally, - Cooling the laminate layer to form a solid laminate layer (3), - Optionally, trim the edges of the solid laminate layer (3). - The thickness of the solid laminate layer (3) is reduced by stretching the solid laminate layer by applying stretching force only in the longitudinal direction or only in the transverse direction within a stretching apparatus, wherein the reduction in the thickness of the solid laminate layer as a result of the stretching is preferably at least 50%, more preferably at least 60%, and even more preferably at least 65%, and - Optionally, trim the edges of the stretched solid laminate layer (3). The method according to any one of claims 1 to 8, as provided by [the present invention].

10. The method according to any one of claims 1 to 9, comprising laminating the laminate layer (3) onto the metal sheet to produce a laminated metal sheet without interrupting a continuous process.

11. The method according to any one of claims 1 to 10, wherein the metal sheet is steel, preferably the steel is uncoated cold-rolled steel, tinplate, ECCS (also known as TFS), TCCT (registered trademark), galvanized steel, or aluminum-plated steel.

12. A laminated metal sheet (9) for packaging that can be obtained or obtained by the method described in any one of claims 1 to 11, The laminated metal sheet comprises a metal sheet (1) and a laminate layer (3) covering at least one side of the metal sheet. The laminate layer (3) includes an adhesive layer (A) and a bulk layer (B), The adhesive layer is bonded to the metal sheet and contains or contains a copolyester having 5-30% ethylene-isophthalate units, 80-95% ethylene-terephthalate units, and 0-5% other units. The bulk layer essentially consists of poly(ethylene terephthalate) having at least 90% ethylene-terephthalate units. The adhesive layer (A) and the bulk layer (B) may each optionally contain additives such as slip additives and antiblocking particles. The bulk layer (B) may optionally further contain colorants, dyes, toners, or pigment particles. In the laminated metal sheet, the Euclidean distance D between the first ATR FTIR spectrum and the second ATR FTIR spectrum of the adhesive layer (A) ａｄｈ The value of is in the range of 0 to 0.10, and the Euclidean distance D of the bulk layer (B) between the first ATR FTIR spectrum and the second ATR FTIR spectrum of the bulk layer (B) is ｂｕｌｋ The value has a range of 0.10 or greater. The first ATR-FTIR spectrum is measured using an ATR-FTIR spectrometer with an incident IR beam in a first in-plane direction relative to the mechanical direction of the laminated metal sheet or the corresponding self-supporting laminate layer. The second ATR FTIR spectrum is measured using the ATR FTIR spectrometer after rotating the laminated metal sheet or the corresponding self-supporting laminate layer to a second in-plane direction at an angle α selected in the range of 70° to 110° within the plane of the laminate layer. The first and second ATR-FTIR spectra are measured in a spectral range including the range of 1160 to 1520 cm －１ and are measured in a spectral range including the range of 1160 to 1520 cm D ｂｕｌｋ / D ａｄｈ The laminated metal sheet (9) is preferably at least 1.

50.

13. The laminate layer, as a result of stretching during the manufacturing of the laminate layer by applying stretching force only in the longitudinal direction or only in the transverse direction within the stretching apparatus, is mainly or completely oriented in the direction of the machine, or mainly or completely oriented perpendicular to the direction of the machine. The laminated metal sheet (9) according to claim 11 or 12, wherein the reduction in the thickness of the solid laminate layer as a result of the stretching is at least 50%, more preferably at least 60%, and even more preferably at least 65%.

14. The adhesive layer (A) contains or comprises (i) 5 to 15% by weight of ethylene isophthalate units, 80 to 95% by weight of ethylene terephthalate units, and 0 to 5% by weight of other components, or (ii) contains or comprises 60 to 100% by weight of amorphous copolyester, 0 to 40% by weight of crystalline polyester or copolyester or a mixture thereof, for example, polyethylene terephthalate, and 0 to 10% by weight of other components. The main polymer resin used in the one or more additional top layers is poly(ethylene terephthalate) having at least 90% ethylene terephthalate units. The adhesive layer (A) and the bulk layer (B) may each optionally contain additives such as slip additives and antiblocking particles. The laminated metal sheet (9) according to any one of claims 11 to 13, wherein the bulk layer (B) may optionally further contain a colorant, dye, toner, or pigment particles.

15. Use of a laminated metal sheet according to any one of claims 12 to 14 for manufacturing a seamless container body, or for manufacturing a can lid or can end, The seamless container body is manufactured by drawing a cup having an end wall and side walls rising from the periphery of the end wall from the laminated metal sheet (1). At least one side of the cup is covered with the laminate layer (3) for use.

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