JP2002264256A - Film-laminated metal sheet for container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a film-laminated metal sheet for a container which ensures the facility to unload the contents and has characteristics such as moldability, adhesion and taste characteristics which are required for container fabrication. SOLUTION: In this film-laminated metal sheet for a container, a resin film A is a biaxially stretched polyester film showing that the melt point is 240 to 300 deg.C and a carboxyl terminal group is 10 to 50 equivalent/ton and further, substantially no isophthalic acid component is contained as an acidic component, and a resin film B is the biaxially stretched polyester film and contains 0.10 to 2.0% of a wax component to the resin in terms of mass ratio. Further, the resin film B is laminated on the surface of a metal sheet which serves as the internal face side of the container and the resin film A is laminated on the surface of the metal sheet which serves as the external face side, after molding the container. A carnauba wax or a stearate is added as the wax component.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film-laminated metal plate used mainly for can bodies and lids of food cans. More specifically, the present invention relates to a film-laminated metal plate for a container which has good moldability and adhesion in a can-making process, and has excellent content take-out properties and taste characteristics after filling contents.

[0002]

2. Description of the Related Art Conventionally, metal plates such as tin-free steel (TFS) and aluminum, which are materials for metal cans used for food cans, have been coated. This coating technique has problems that not only the baking process is complicated, but also requires a great deal of processing time and that a large amount of solvent is discharged. Therefore, in order to solve these problems, many methods of laminating a thermoplastic resin film on a heated metal plate have been proposed.

Many of these proposals relate to the improvement of the adhesion and moldability between a film and a metal plate as a base material, and the technical idea is generally based on the application of a film having a polar group (such as a polyester resin). (For example, see JP-A-63-
JP-A-236640), and an increase in surface free energy typified by activation by treatment such as corona discharge on the film surface (for example, JP-A-5-200961).

[0004] When the laminated metal plate proposed above is used for food canning, there is a problem in that when the contents are taken out of the container, the contents adhere firmly to the inner surface of the container, and it is difficult to take out the contents. is there. Since this problem is closely related to the consumer's willingness to purchase, it is extremely important to improve the ease of taking out contents in order to ensure the consumer's willingness to purchase. Nevertheless, no consideration has been given to improving the ease of taking out the contents.

[0005]

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in consideration of the above circumstances, and has a feature of ensuring that contents can be taken out.
An object of the present invention is to provide a film-laminated metal plate for a container having the moldability, adhesion, and taste characteristics required for container processing.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that a biaxially oriented polyester resin having a highly controlled film structure without substantially containing an isophthalic acid component. It has been found that this object is achieved by adding a wax component to the film. That is, the gist of the present invention is as follows.

(1) A biaxially stretched polyester film having a melting point of 240 to 300 ° C., a carboxyl terminal group of 10 to 50 equivalents / ton, and substantially not containing an isophthalic acid component as an acid component is a resin film A; When a resin film B, which is a stretched polyester resin film and further contains a wax component in an amount of 0.10 to 2.0% by mass with respect to the resin, is a metal plate on the inner surface side of the container after molding the container A film-laminated metal plate for a container, characterized in that a resin film B is laminated on the surface of the resin film B and a resin film A is laminated on the surface of the metal plate on the outer surface side of the container.

(2) The film-laminated metal plate for a container according to the above (1), which contains carnauba wax or stearic acid ester as a wax component. (3) Resin film A and resin film B after lamination
3. The film-laminated metal plate for a container according to claim 1, wherein a region where the birefringence is 0.02 or less is less than 5 μm in a film thickness direction from a contact interface with the metal plate.

(4) The above (1) to (3), wherein 95% by mass or more of the polyester units constituting the resin films A and B are ethylene terephthalate units and / or ethylene naphthalate units. The film-laminated metal plate for a container according to any one of the above. (5) Laminated resin film A, resin film B
The film-laminated metal plate for a container according to any one of the above (1) to (4), wherein the refractive index in the thickness direction is 1.500 or more.

(6) The resin film A and the resin film B according to any one of the above (1) to (5), wherein the relaxation time of the carbonyl portion in the structural analysis by solid-state high-resolution NMR is 270 msec or more. Film laminated metal plate for container. (7) The resin film B is composed of at least two layers, and the resin film B is formed only on the uppermost layer in contact with the contents.
The film-laminated metal plate for a container according to any one of the above (1) to (6), comprising a wax component in an amount of 0.10 to 2.0% by mass with respect to the resin.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. In the present invention, a polyester film is used for the film (resin film A, resin film B), and the polyester has a melting point (melting peak temperature) of 240 in DSC.
It is necessary that the melting point be from 300 to 300 ° C in order to improve the taste characteristics, but it is preferable that the melting point is from 245 to 300 ° C, and it is particularly preferable that the melting point be from 246 to 300 ° C. In the present invention, “good taste characteristics” refers to the degree to which the flavor of the contents is not impaired by the adsorption of the scent component of the contents of the can to the film or the leaching from the film.

Further, the film used in the present invention must have a polyester having a carboxyl terminal group content of 10 to 50 equivalents / ton in order to improve adhesion to a metal plate and taste characteristics after retort. Since the carboxyl terminal group has polarity, the adhesion increases as the amount increases, but the flavor components of the contents are easily adsorbed and the taste characteristics deteriorate. If the amount of carboxyl end groups is less than 10 equivalents / ton, good adhesion cannot be obtained, and if it exceeds 50 equivalents / ton, taste characteristics deteriorate. It is desirable that the amount of the carboxyl terminal group of the polyester is 15 to 48 equivalents / ton, particularly preferably 15 to 45 equivalents / ton, since the long-term storage property is excellent.

It is necessary that the polyester used in the present invention does not substantially contain an isophthalic acid component as an acid component. However, the taste characteristics after retorting are good, and the generation of abrasion powder in a can-making process is reduced. From the viewpoint of suppression, it is preferable to use ethylene terephthalate and / or ethylene naphthalate as a main component. In addition, that it does not contain isophthalic acid substantially means that it does not intentionally contain isophthalic acid other than those inevitably mixed as impurities.

[0014] The low molecular weight component having an insufficient degree of polymerization contained in the film is easily eluted into the contents such as beverages.
Deteriorates taste characteristics. Since the polyester does not substantially contain the isophthalic acid component, the low molecular weight component having an insufficient degree of polymerization in the film is reduced, so that the low molecular weight component eluted in the content is reduced, and the deterioration of taste characteristics is reduced. Is prevented.

The polyester containing ethylene terephthalate and / or ethylene naphthalate as a main component is a polyester containing 95% by mass or more of the polyester containing ethylene terephthalate and / or ethylene naphthalate as a main component. When the content is 97% by mass or more, the taste characteristics are good even when the contents are filled in a metal can for a long period of time, so that it is more preferable.

On the other hand, other dicarboxylic acid components and glycol components may be copolymerized as long as taste characteristics are not impaired. Examples of the dicarboxylic acid component include diphenylcarboxylic acid, 5-sodium sulfoisophthalic acid and phthalic acid. Aromatic dicarboxylic acids, oxalic acid, succinic acid, adipic acid, sebacic acid, dimer acid, maleic acid, aliphatic dicarboxylic acids such as fumaric acid, aliphatic dicarboxylic acids such as cyclohexanedicarboxylic acid, p-oxybenzoic acid and the like Oxycarboxylic acids and the like can be mentioned.

On the other hand, examples of the glycol component include aliphatic glycols such as ethylene glycol, propanediol, butanediol, pentanediol, hexanediol and neopentyl glycol; finger-ring glycols such as cyclohexanedimethanol; bisphenol A;
Examples thereof include aromatic glycols such as bisphenol S, diethylene glycol, and polyethylene glycol. In addition, two or more of these dicarboxylic acid components and glycol components may be used in combination.

As long as the effects of the present invention are not impaired, polyfunctional compounds such as trimellitic acid, trimesic acid, and trimethylolpropane may be copolymerized.

The components contained in the polyester used in the present invention in a small amount include diethylene glycol, polyethylene glycol, cyclohexane dimethanol, sebacic acid, dimer acid and the like. For applications having severe taste characteristics, diethylene glycol, polyethylene glycol and the like can be mentioned. .

In the present invention, the resin film (resin film B) on the inner surface side of the container after the container is formed further contains a wax component in an amount of 0.10 to 2.0% by mass with respect to the resin. Stipulate. The reason why the wax component is contained as an additive is to lower the surface energy of the film and to impart lubricity to the film surface. The effect makes it difficult for the contents to adhere to the film, and the effect reduces the coefficient of friction of the film surface, thereby making it possible to dramatically improve the takeout of the contents.

The reason for limiting to 0.10% or more is that 0.1%
When it is less than 0%, the effect of the above becomes poor,
This is because the content is not easily taken out. Further, the reason why the content is limited to 2.0% or less is that if the content exceeds 2.0%, the retrievability of contents is almost saturated, so that no particular effect can be obtained, and also in a region where film formation technology is difficult. This is because productivity is poor and cost increases.

As the wax component to be added, an organic / inorganic lubricant can be used, but an organic lubricant such as a fatty acid ester is desirable. Among them, carnauba wax, which is one of the plant waxes and natural wax (mainly wax) Ingredient: CH
₃ (CH ₂ ) ₂₄ COO (CH ₂ ) ₂₉ CH 3, and also contains components composed of various aliphatics and alcohols. ) Alternatively, stearic acid esters are preferred because of their large effects and easy addition to the film in terms of molecular structure. In addition, the polyester film containing the above-mentioned wax can be manufactured by blending a predetermined amount of the wax with the polyester and then using a usual film forming method.

The above effects cannot be obtained by applying a wax component to the film surface. This is because a canned food or the like is subjected to a retort treatment for sterilization after filling the contents, in which case the wax previously applied to the surface is absorbed by the contents. When added in a film as in the present invention, the wax gradually thickens on the surface during the retort treatment, so that the whole is not absorbed by the contents, and thus the above-mentioned effects can be surely exhibited. Becomes

The structure of the film after being laminated on a metal plate is such that a region having a birefringence of 0.02 or less is less than 5 μm in a film thickness direction from a contact interface with the metal plate. Is desirable. In the production of a laminated metal plate, it is usual to bond a film by contacting the film with a heated metal plate and pressing the film to melt the film resin at the metal plate interface and wet the metal plate. Therefore, in order to ensure the adhesion between the film and the metal plate, the film needs to be melted, and the film birefringence of the portion in contact with the metal plate after lamination necessarily decreases. .

If the birefringence of the film in this portion is 0.02 or less as specified in the present invention, it indicates that the film has sufficient wetness for lamination during lamination, and therefore, excellent adhesion can be ensured. It becomes possible.

As the birefringence of such a polyester resin, a value determined by the following measuring method is employed. Using a polarizing microscope, the retardation in the cross-sectional direction of the film after removing the metal plate of the laminated metal plate is measured, and the birefringence in the cross-sectional direction of the resin film is determined. The linearly polarized light incident on the film is decomposed into linearly polarized lights in two principal refractive index directions. At this time, the vibration of light in the high refractive index direction becomes slower than that in the low refractive index direction, so that a phase difference occurs when the light passes through the film layer. This phase difference is called a retardation R, and the relationship with the birefringence △ n is defined by Expression (1).

Δn = R / d (1) where d is the thickness of the film layer. Next, a method of measuring retardation will be described. By passing monochromatic light through a polarizing plate, it becomes linearly polarized light, and this light is incident on a sample (film). Since the incident light causes retardation as described above, the light becomes elliptically polarized light after passing through the film layer. This elliptically polarized light becomes linearly polarized light having an angle of θ with respect to the vibration direction of the first linearly polarized light by passing through the Senarmont-type compensator. This θ is measured by rotating the polarizing plate. The relationship between retardation R and θ is defined by equation (2). R = λ · θ / 180 (2) where λ is the wavelength of monochromatic light, and the birefringence Δn is defined by Expression (3) derived from Expressions (1) and (2). Δn = (θ · λ / 180) / d (3) The thickness of the portion where the birefringence is 0.02 or less is 5 μm from the contact interface with the metal plate in the film thickness direction.
It is desirable to limit the area to less than. The reason is as follows.

The film used in the present invention has a feature that the molecular mobility represented by the relaxation time T1ρ of the carbonyl portion in the structural analysis by solid-state high-resolution NMR is low, and thus the film has excellent moldability and impact resistance. However, when the film is completely melted, the effect is poor, and there is a disadvantage that crystallization is easily caused in the subsequent processing and heat treatment, and the formability of the film is deteriorated.

However, as described above, in order to ensure film adhesion, melt wetting of the film is essential. According to the results of extensive studies by the present inventors, the portion where the film is melted, that is, the birefringence of the film is 0.02.
By regulating the thickness of the following parts to less than 5 μm,
It is possible to achieve both moldability and impact resistance at a high level while ensuring adhesion.

The film used in the present invention needs to be biaxially stretched from the viewpoint of heat resistance and taste characteristics. The method of biaxial stretching may be any of simultaneous biaxial stretching and sequential biaxial stretching, but the stretching conditions and heat treatment conditions are specified, and the refractive index in the thickness direction of the film is 1.500.
The above is preferred in terms of improving laminating property and draw formability. Further, the thickness direction refractive index is 1.51
When it is 0 or more, especially 1.520 or more, even if there is some temperature variation at the time of lamination, the plane orientation coefficient of the film after lamination is determined by the plane orientation coefficient necessary for achieving both moldability and impact resistance. It is preferable because it can be controlled within the range.

Further, the biaxially stretched polyester film used in the present invention may be prepared by drawing 200 to 300
It is preferable that the relaxation time T1ρ of the carbonyl part in the structural analysis by solid-state high-resolution NMR is 270 msec or more from the viewpoint of improving formability when processing the neck part after receiving a heat history of about ° C.

Further, the film used in the present invention has a polyester thermal crystallization parameter ΔTcg (heated thermal crystallization temperature−glass transition temperature) of not less than 60 ° C. and not less than 150 ° C. in terms of improving formability when processing the neck portion. The following is preferable, and especially preferable is 70 to 150 degreeC. Such a method of imparting thermal crystallinity can be achieved by controlling the catalyst, the molecular weight, and the content of diethylene glycol.

The structure of the biaxially stretched polyester film used in the present invention may be either a single layer or multiple layers. In the case of a multi-layer structure, it is necessary that wax is added to the uppermost layer of the film (resin film B) in contact with the contents, and wax is added only to the uppermost layer of the film from the viewpoint of economy and the like. Is desirable. The thickness of the film is preferably from 3 to 50 μm, and more preferably from 8 to 30 μm, from the viewpoint of moldability after lamination on metal, coatability to metal, impact resistance and taste characteristics.

The method for producing the film itself (including the laminated film) is not particularly limited. For example, after drying each polyester as required, the polyester alone and / or each is supplied to a known melt laminating extruder. The sheet is extruded into a sheet form from a slit-shaped die, brought into close contact with a casting drum by a method such as electrostatic application, and cooled and solidified to obtain an unstretched sheet.

The unstretched sheet is stretched in the longitudinal and width directions of the film to obtain a biaxially stretched film. The stretching ratio can be arbitrarily set according to the degree of orientation, strength, elastic modulus, and the like of the target film, but is preferably a tenter method in view of the quality of the film, and after stretching in the longitudinal direction, Desirable are a sequential biaxial stretching method in which the film is stretched in the width direction, and a simultaneous biaxial stretching method in which the film is stretched in substantially the same length and width directions.

Next, a production method for laminating these films on a metal plate will be described. In the present invention, a method is used in which a metal plate is heated at a temperature exceeding the melting point of the film, and the resin film is brought into contact with both surfaces thereof using a pressure roll (hereinafter, referred to as a laminating roll) and laminated (heat-fused).

The lamination conditions are not particularly limited as long as the film structure specified in the present invention can be obtained. For example, if the temperature at the start of lamination is 2
The temperature history of the film during lamination is 80 ° C or higher.
It is preferable to set the range to 20 msec. In order to achieve such lamination conditions, cooling during bonding is required in addition to lamination at high speed. The pressure at the time of lamination is not particularly specified.
30 kgf / cm ² is preferred. If this value is too low,
Even when the melting point is higher than the melting point, it is difficult to obtain sufficient adhesion because the time is short. Further, if the pressure is large, the performance of the laminated metal plate is not inconvenient, but the force applied to the laminating roll is large and the equipment strength is required, which leads to an increase in the size of the apparatus, which is uneconomical.

As the metal plate, an aluminum plate or a mild steel plate which is widely used as a material for cans can be used. In particular, a two-layer film comprising a lower layer made of chromium metal and an upper layer made of chromium hydroxide is formed. Surface treated steel sheet (so-called TF
S) and the like are optimal. The adhesion amounts of the metal chromium layer and the chromium hydroxide layer of TFS are not particularly limited, either, but from the viewpoint of adhesion and corrosion resistance after processing, the metal chromium layer is 70 to 200 mg / m ² , The hydroxide layer is desirably in the range of 10 to 30 mg / m ² .

[0039]

Embodiments of the present invention will be described below. A cold-rolled, annealed, temper-rolled steel sheet having a thickness of 0.18 mm and a width of 977 mm was subjected to degreasing, pickling, and chromium plating to produce a chromium-plated steel sheet. Chrome plating is C
After chromium plating in a chromium plating bath containing rO ₃ , F ⁻ , and SO ₄ ²⁻ , and intermediate rinsing, electrolysis was carried out with a chemical conversion treatment solution containing CrO ₃ and F ⁻ . At this time, the electrolysis conditions (current density, amount of electricity, etc.) were adjusted to adjust the metal chromium adhesion amount to 120 mg / m ² and the chromium hydroxide adhesion amount to 15 mg / m ² .

Next, using the metal strip laminating apparatus shown in FIG. 1, the chromium-plated steel sheet 1 obtained above was heated by the metal strip heating apparatus 2, and was laminated on one side of the chrome-plated steel strip 1 by the laminating roll 3. Various films 4a shown in Table 1 as a resin film (resin film B) on the inner surface side of the container after the molding of the container, and various films 4b as a resin film (resin film A) on the outer surface side of the container after the molding of the container on the other surface. Was laminated (thermal fusion) to produce a laminated metal band. As the resin film 4a on the inner surface side of the container after the container was formed, a resin film 4b on the outer surface side of the container to which wax was added was used. Table 1 shows the content of the laminated resin film. The laminating roll 3 was of an internal water-cooling type, and cooling water was forcibly circulated during lamination to perform cooling during film bonding.

The properties of the biaxially stretched polyester film used are as follows (1) to (5), and the properties of the laminated metal plate manufactured by the above method are as follows (6).
It measured and evaluated by the method of-(10). (1)-
(4) shows the characteristics of the original film before lamination.
The properties of (1), (3) and (4) do not change after lamination.

(1) Amount of carboxyl terminal group of polyester The polyester was dissolved in O-cresol / chloroform (mass ratio: 7/3) at 90 to 100 ° C. for 20 minutes, and potentiometric titration was performed with alkali.

(2) Refractive index in the thickness direction of the film Measured with an Abbe refractometer using sodium D line (wavelength 589 nm) as a light source. (3) Melting point of polyester Thermal crystallization parameter The polyester was dried, melted and rapidly cooled, and then subjected to a differential scanning calorimeter (DSC-Perkin Elmer Co., Ltd.).
(Type 2) at a heating rate of 16 ° C./min.

(4) Relaxation time T1ρ by solid-state high-resolution NMR The solid-state NMR measurement device is a JEOL spectrometer JNM-GX270, a JEOL solid-state amplifier, a MAS controller NM-GSH27MU, and a JEOL probe NM-GSH27T. Using. The measurement is the T1ρ of the ¹³ C nucleus.
(Longitudinal relaxation in rotation coordinates) Measurement was performed. The measurement is
Temperature 24.5 ° C, humidity 50% RH, static magnetic field strength 6.34
Under T (tesla), the resonance frequencies of ¹ H and ¹³ C are 270.2 MHz and 67.9 MHz, respectively. In order to eliminate the influence of the anisotropy of the chemical shift, a MAS (magic angle rotation) method was adopted. The rotation speed is 3.5 to 3.7 kHz
I went in. The condition of the pulse sequence is 90 ° with respect to ¹ H,
Pulse width 4μsec, rocking magnetic field strength 62.5kHz
z. The contact time of CP (cross-polarization), which transfers ¹ H polarization to ¹³ C, is 1.5 msec. The holding time τ is 0.001, 0.5, 0.7,
1, 3, 7, 10, 20, 30, 40, and 50 msec were used. The free induction decay (FID) of the ¹³ C magnetization vector after the retention time τ was measured (high power coupling was performed to eliminate the influence of dipole interaction due to ¹ H during the FID measurement. S / N Was performed 512 times in order to improve). Also, the pulse repetition time
Performed between 5 and 15 seconds.

The value of T1ρ is usually I (t) = Σ (Ai) exp (-t / T1
ρi), and the slope of the peak intensity observed for each retention time can be determined by semilogarithmic plotting. Here, Ai is the ratio of the component to T1ρi.

Here, a two-component system (T1ρ1: amorphous component, T1
ρ2: crystal component), and the value was determined by the least squares fitting using the following equation. I (t) = fa1 ・ exp (-t / T1ρ1) + fa2 ・ exp (-t / T1ρ2) fa1: Ratio of component to T1ρ1 fa2: Ratio of component to T1ρ2 fa1 + fa2 = 1 Here, T1ρ2 is T1ρ Used.

(5) Birefringence of polyester film The retardation in the cross-sectional direction of the film after the metal plate of the laminated metal plate was removed was measured using a polarizing microscope.
The birefringence in the cross-sectional direction of the film was determined.

(6) Content take-out property The laminated metal plate was cup-formed in a drawing step using a draw forming machine at a blank diameter of 100 mm and a draw ratio (diameter before molding / diameter after molding) of 1.88. . Subsequently, the contents in which the egg, meat, and oatmeal were uniformly mixed were filled into the cup, and the lid was tightly wound, followed by retort treatment (130 ° C. × 9).
0 min). Then, remove the lid, turn the cup upside down, shake it by hand two or three times to take out the contents, and observe the degree of contents remaining inside the cup to evaluate the degree of ease of taking out the contents. did. (Regarding the score) ：: The contents are easily taken out, and there is no attached matter on the inner surface of the cup after taking out. ○: It is difficult to take out the contents only by shaking with hand,
It can be easily taken out with a spoon etc., and there is almost no deposit on the inner surface of the cup after taking out. ×: It is difficult to take out the contents only by shaking with hand,
The contents cannot be taken out unless scraped out with a spoon or the like, and a lot of deposits are found on the inner surface of the cup after being taken out.

(7) Formability After wax was applied to the laminated metal plate, a disk having a diameter of 179 mm was punched out to obtain a shallow drawn can with a drawing ratio of 1.60. Then, with respect to this drawing cup, drawing ratios of 2.10 and 2.
Redrawing was performed at 80. Then, after performing doming forming according to a conventional method, trimming was performed, and then neck-in-flange processing was performed to form a deep drawn can. Attention was paid to the neck-in portion of the deep drawn can thus obtained, and the degree of damage to the film was visually observed. (Regarding the score) ：: The film is not damaged after molding and no peeling of the film is observed. ：: Moldable, but film peeling is observed. X: The can was broken and molding was impossible.

(8) Adhesiveness A sample for peel test (15 mm wide × 120 mm long) was taken from the body of the can with respect to the can that could be molded in the above (7).
Was cut out. A part of the film was peeled off from the long side end of the cut sample, and the part of the film peeled off by the tensile tester was opened in the opposite direction (angle: 180 °) to the chromium-plated steel sheet from which the film was peeled, and pulled. Speed 30mm /
A peel test was performed at a minimum to evaluate the adhesion. In addition,
The surface to be measured for adhesion was the inner surface of the can.に つ い て: 0.15 kg / 15 mm or more.

○: 0.10 kg / 15 mm or more, 0.15 kg / 15
less than mm. X: Less than 0.10 kg / 15 mm.

(9) Impact resistance The can which was moldable in the above (7) was filled with water,
After dropping 10 pieces of each test from a height of 1.25 m to the PVC tile floor, apply a voltage of 6 V to the electrode and the metal can, read the current value 3 seconds later, and calculate the average value after measuring the 10 cans. I asked. (Score) ：: Less than 0.01 mA. ：: 0.01 mA or more and less than 0.1 mA. X: 0.1 mA or more.

(10) Taste Characteristics After the retort treatment at 120 ° C. for 30 minutes was performed on the can which was moldable in the above (7), the perfume aqueous solution d-limonene 25 was added.
350 ml of an aqueous ppm solution was filled, sealed at 40 ° C., allowed to stand for 45 days, opened, and then subjected to a sensory test to evaluate changes in odor according to the following criteria. ：: Little change in odor was observed. Δ: Slight change is observed in odor. X: A large change is seen in the odor. The evaluation results are shown in Table 2.

[0054]

[Table 1]

[0055]

[Table 2]

As shown in Tables 1 and 2, all of the inventive examples within the scope of the present invention exhibited good properties in terms of content take-out property, moldability, adhesion, impact resistance and taste characteristics.

In the examples of the present invention, those containing carnauba wax or stearic acid ester as a wax component are more excellent in taking out contents. If the thickness of the region where the value of the birefringence of the film is 0.02 or less is less than 5 μm from the contact interface with the metal plate, the moldability is more excellent.
When the relaxation time T1ρ is 270 msec or more, the formability is more excellent. When 95% by mass or more of the polyester units constituting the film are ethylene terephthalate units, impact resistance and taste characteristics are more excellent.

On the other hand, the comparative examples out of the range of the present invention have at least one of the content retrievability, taste characteristics and moldability.
One was bad.

[0059]

Industrial Applicability The laminated metal sheet according to the present invention has a good content take-out property, moldability, adhesion, impact resistance and taste characteristics, and is a material for containers for drawing and the like, particularly a material for food can containers. It is suitable as.

[Brief description of the drawings]

FIG. 1 is a diagram showing a main part of a metal plate laminating apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Metal plate (chrome-plated steel plate) 2 Metal band heating device 3 Laminating roll 4a, 4b Film

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 91:06) C08L 91:06) B29K 67:00 B29K 67:00 B29L 7:00 B29L 7:00 ( 72) Inventor Shinsuke Watanabe 1-2-2 Marunouchi, Chiyoda-ku, Tokyo F-term in Nihon Kokan Co., Ltd. 3E086 AD30 BA04 BA13 BA15 BB90 CA01 DA08 4F100 AB01C AB03C AB13C AJ11B AK41A AK41B BA03 BA07 BA10A BA10C BA16 DA01 EJ38A EJ38B GB16 GB23 JA04A JK10 JL01 JN18A JN18B YY00A YY00B 4F210 AA24 AB19 AG01 AG07 QC05 QG01 QG18 4J002 AE032 CF061 CF081 FD172 GF00 GG01

Claims (7)

[Claims] 1. A biaxially oriented polyester film having a melting point of 240 to 300 ° C., a carboxyl terminal group of 10 to 50 equivalents / ton, and substantially not containing an isophthalic acid component as an acid component. When a resin film, which is a polyester resin film and further contains a wax component in an amount of 0.10 to 2.0% by mass with respect to the resin, is referred to as a resin film B, the metal plate on the inner surface side of the container after the molding of the container A film-laminated metal plate for a container, wherein a resin film B is laminated on the surface, and a resin film A is laminated on the surface of a metal plate on the outer surface side of the container. 2. The film-laminated metal plate for a container according to claim 1, wherein the wax component contains carnauba wax or stearic acid ester. 3. The resin film A and the resin film B after lamination have a birefringence of 0.02 or less in a region having a birefringence of less than 5 μm in a film thickness direction from a contact interface with a metal plate. 3. The film-laminated metal plate for a container according to 1 or 2. 4. The method according to claim 1, wherein 95% by mass or more of the polyester units constituting the resin films A and B are ethylene terephthalate units and / or ethylene naphthalate units. Film laminated metal plate for container. 5. The film-laminated metal plate for a container according to claim 1, wherein the resin films A and B have a refractive index in the thickness direction of 1.500 or more. 6. The container film according to claim 1, wherein the relaxation time of the carbonyl portion in the structural analysis of the resin film A and the resin film B by solid-state high-resolution NMR is 270 msec or more. Laminated metal plate. 7. The resin film B is composed of at least two layers, and the resin film B contains a wax component of 0.10 to 2.0% by mass relative to the resin only in the uppermost layer in contact with the contents. The film-laminated metal plate for a container according to any one of claims 1 to 6, which is contained.