JPH06226914A - Metallic plate coated with film, can coated with film and its manufacture - Google Patents

Abstract

PURPOSE:To provide a metallic plate coated with a film which equips corrosion resistance and outward appearance characteristics necessary for the material of various vessels and also has odor retaining properties and characteristics suitable for various wrapping materials especially the wrapping material of contents important in flavor such as a drink and to provide a can coated with the film which has such advantage and a method for manufacturing it. CONSTITUTION:A metallic plate coated with a film is formed by sticking the film of ethylene-vinyl alcohol copolymerized resin on the face of metallic material which becomes at least the inside of a can. A can coated with a film is formed by drawing the metallic plate coated with the film at >=1.1 draw ratio. Further, after the metallic plate coated with the film is drawn at >=1.1 draw ratio, the worked part is constituted of a slope part for performing squeezing work and a bearing part. The can coated with the film is manufactured by using an annular die in which the inclination of the slope part has an angle of 20-30 degrees and performing squeezing work.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film-coated metal plate, a film-coated can and a method for producing the same, and more particularly to a food container, particularly a packaging material for contents such as beer in which flavor (flavor, flavor) is important. The present invention relates to a film-coated metal plate having excellent fragrance-keeping properties, which is particularly preferably used as a film-coated can, a film-coated can using the same, and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, for the purpose of imparting corrosion resistance to a container made of a metal material, it is necessary to coat the surface of the metal material with a resin layer before or after molding the container. It is widely practiced. Then, as a coating method used in such a technique, a coating liquid obtained by dissolving or dispersing an epoxy-based, phenol-based, or vinyl chloride-based resin in an appropriate solvent is applied to the surface of the metal material, and then heated. The method of removing the solvent and curing the resin layer to form a resin film on the surface of the metal material is carried out.

On the other hand, there has been proposed a method of coating the surface of a metal material by laminating a resin film on the surface of the metal material. For example, a film coating layer of thermoplastic polyester or polyester ether is provided on the inner surface of the container of the metal material. Methods (JP-B-58-47346, JP-A-60-172637, JP-B-61-51987).

[0004]

However, when a container made of a metal material having a resin film formed by the above-mentioned coating on its surface is used as a food container, the resin component extracted from the resin film into the content food product. The content of the food is generally large, and the sorption of the flavor component contained in the food content to the resin film is also large. Therefore, there is a problem that the flavor of the food content tends to be impaired.

On the other hand, in recent years, with the increasing demand for the taste of beverages and foods, there has been a demand for a method of coating a metal material that reduces the factors affecting foods as much as possible. When the container formed by laminating the metal material was a beer container, the sorption amount of ethyl acetate, which is a flavor component of beer, on the polyester film was measured, and the container was formed by the above coating method. It was confirmed that the dramatic effect was not exhibited as compared with the resin film. Therefore, the appearance of a surface-coated metal material and a food container made of such a metal material, which are more effective, is desired.

Therefore, as a result of extensive studies by the present inventor, a film-coated metal plate obtained by laminating a specific resin film on a metal material has been found to have the adhesiveness of a resin film, corrosion resistance, required for various container materials, It has been found that, in addition to having appearance characteristics, it has a small sorption amount of flavor components when used as a food container and also has an excellent aroma retaining property.

The present invention has been made on the basis of such findings, and an object of the present invention is that the resin film has excellent suitability as a container material such as adhesion, corrosion resistance and appearance characteristics, and a flavor component. (EN) Provided are a film-coated metal plate suitable for use as a container material for contents in which flavor of beverages is important, a film-coated can made of the same, and a method for producing the same.

[0008]

The constitution of the present invention for solving the above-mentioned problems is characterized in that an ethylene / vinyl alcohol copolymer resin film is adhered to at least a surface of a metal material to be an inner surface of a can. A film-coated metal plate which is a film-coated metal plate in which an ethylene / vinyl alcohol copolymer resin film is adhered to at least the surface of the metal material to be the inner surface of the can, and is drawn by a drawing ratio of 1.1 or more. It is a film-coated can that features
A film-coated metal plate having an ethylene / vinyl alcohol copolymer resin film adhered to at least the inner surface of the can is used, and the film-coated metal plate has a drawing ratio of 1.1.
After the drawing is performed as described above, the working portion is composed of an inclined part and a bearing part for performing the ironing process, and the ironing process is performed by using an annular die in which the inclination angle of the inclined part is 2 to 30 degrees. A method for producing a film-coated can, which is characterized in that

The film-coated metal sheet, the film-coated can and the method for producing the same according to the present invention will be described in more detail below. Film-Coated Metal Plate The film-coated metal plate of the present invention is one in which an ethylene / vinyl alcohol copolymer resin film is adhered to at least the surface of the metal material to be the inner surface of the can.

As the metal material, aluminum, aluminum alloy, steel, etc. are preferably used, and the form thereof is such that at least the ethylene / vinyl alcohol copolymer resin film can be adhered to the inner surface of the can. Of course, it may be not only plate-shaped or sheet-shaped but also foil-shaped.

Here, at least the surface that should be the inner surface of the can is the surface that becomes the inner surface when the film-coated metal plate is formed into a can. The whole or a part of at least one side of a plate.

The metal material is preferably surface-treated for the purpose of improving the corrosion resistance and the adhesion to the film. Specifically, for example, a surface treatment such as a phosphoric acid chromate treatment on aluminum, a tin plating treatment on a steel plate, or an electrolytic chromic acid treatment improves the corrosion resistance of the metal material and the adhesion to the film. Further, for example, zirconium salt-based chemical conversion treatment of aluminum, which is widely used in the field of cans, or composite coating treatment of an organic substance and a metal salt of Cr, Zr, Ti or the like, is preferably applied as the surface treatment of this metal material. It is possible.

There is no particular limitation on the thickness of the metal material, and a desired container may be molded and the thickness that can withstand long-term use may be appropriately determined. Further, when the surface treatment is performed on the metal material, it is preferable that the amount of the film is such that desired corrosion resistance and adhesion to the film can be obtained.

Next, the ethylene / vinyl alcohol copolymer resin film which is brought into close contact with at least the inner surface of the can of the metal material will be described. Here, the resin film forms the inner surface of the can when the film-coated metal plate is molded into the can, and comes into contact with the contents for a long period of time. Therefore, when the content is a beverage or a food, the relationship between the resin film and the flavor is particularly important from the viewpoints of food hygiene safety and preservation of the original quality of the beverage or food.

Considering the reason why the original flavor of the beverage or food changes, from the viewpoint of the interaction between the beverage or food and the resin film on the inner surface of the can, (1) sorption of the flavor component contained in the beverage onto the resin film ( 2) Transfer of trace components from the resin film to beverages or foods, (3) Chemical reaction occurs between the components transferred from the resin film and the components of the beverage or food, the original flavor component disappears, or foreign substances It is thought that there are three reasons why the flavor balance is lost due to the change to.

The transfer of the flavor component to the resin film is
Sorption of flavor components on the resin film → Follow the process of dissolution / diffusion in the resin film. Therefore, sorption refers to the dissolution and diffusion in the resin film, and the sorption to the resin film is
The usual idea of gas permeation is helpful, and it is considered that a resin film having a better gas barrier property is more excellent in aroma retention.

Among various plastic films, the ethylene / vinyl alcohol copolymer resin film has the highest level of oxygen gas barrier property, and nitrogen gas,
It also has excellent gas barrier properties against carbon dioxide gas and helium gas.

In the film-coated metal plate of the present invention, the ethylene / vinyl copolymer resin film is brought into close contact with at least the surface of the metal material to be the inner surface of the can. This ethylene
The vinyl alcohol copolymer resin is a copolymer of ethylene and vinyl alcohol, and the ethylene copolymerization ratio thereof is usually 20 to 70 mol%, preferably 30 to 50 mol%. When this ratio is less than 20 mol%, the oxygen gas barrier property of the ethylene / vinyl alcohol copolymer resin film is not sufficient, so that good aroma retaining property may not be obtained. On the other hand, if it exceeds 70 mol%,
Oxygen gas barrier properties of the ethylene / vinyl alcohol copolymer resin film may be deteriorated, and good aroma retaining property may not be obtained. That is, the oxygen permeability of the ethylene / vinyl alcohol copolymer resin film increases with an increase in the ethylene copolymerization ratio when dried. Also, when water is absorbed, it becomes O
The intramolecular and intermolecular cohesive energies due to the H group are reduced and the oxygen permeability is increased. On the other hand, since the water absorption rate decreases as the ethylene copolymerization ratio, which is a hydrophobic component, increases, the increase in oxygen permeability due to the influence of water tends to be suppressed. Due to these contradictory phenomena, the oxygen permeability of the ethylene / vinyl alcohol copolymer resin film at 100% RH shows a minimum value in the vicinity of the ethylene copolymerization ratio of 44 mol%. Therefore, in order to make the gas barrier property of the ethylene / vinyl alcohol copolymer resin film good and to make the aroma retention sufficient, it is preferable that the ethylene copolymerization ratio is in the above range.

The method for producing the ethylene / vinyl alcohol copolymer resin film is not particularly limited, and for example, it is obtained by extruding an ethylene / vinyl alcohol copolymer resin with a known extruder and then forming a film. It may be present or may be obtained by further subjecting it to a stretching treatment and a heat setting treatment.

The thickness of the ethylene / vinyl alcohol copolymer resin film is not particularly limited, but is preferably 3 to 100 μm. When the thickness is less than 3 μm, the laminating workability is significantly deteriorated, and sufficient processing corrosion resistance may not be obtained. On the other hand, 100
Even if it is thicker than μm, the effect equivalent to that is not exhibited, and it may be disadvantageous in terms of cost.

Next, a method for laminating the ethylene / vinyl alcohol copolymer resin film on the surface of the metal material will be described. The ethylene / vinyl alcohol copolymer resin film can be adhered to the surface of the metal material by heat fusion.

Specifically, ethylene
The surface to which the vinyl alcohol copolymer resin film should be adhered is heated to a predetermined temperature, and this heating surface and ethylene
The vinyl alcohol copolymer resin film is brought into contact with the film to melt the contact surface of the film, thereby bringing the film into close contact with the metal material.

Here, the surface temperature of the metal material immediately before contacting the ethylene / vinyl alcohol copolymer resin film is required to be the melting point (Tm) to (Tm + 150 ° C.) of the ethylene / vinyl alcohol copolymer resin film. is there. The melting point (Tm) here is 10 ° C./min.
It is the temperature determined from the endothermic peak of the differential thermal analysis performed at the heating rate of. If the surface temperature of the metal material immediately before contacting the ethylene / vinyl alcohol copolymer resin film is lower than the melting point (Tm) of the ethylene / vinyl alcohol copolymer resin film, the ethylene / vinyl alcohol copolymer resin film is not sufficiently melted. In some cases, adhesion with metal materials is not sufficient. On the other hand, if the temperature is (Tm + 1
If it exceeds 50 ° C., the ethylene / vinyl alcohol copolymer resin film laminated on a metal material is significantly deteriorated by heat, and the gas barrier property is deteriorated so that sufficient aroma retaining property may not be obtained.

In order to obtain the film-coated metal sheet of the present invention, it is necessary to control the cooling conditions after the ethylene / vinyl alcohol copolymer resin film is laminated on the metal material as described above.

Specifically, a metal material laminated with an ethylene / vinyl alcohol copolymer resin film is a crystal melting start temperature (Ts) or lower of the ethylene / vinyl alcohol copolymer resin film, preferably (Ts-20 ° C.) or lower. To 60 ° C. within 60 seconds. The crystal melting start temperature (Ts) referred to here is the temperature at which the endothermic reaction of the ethylene / vinyl alcohol copolymer resin film starts, which is determined by the differential thermal analysis performed at a heating rate of 10 ° C / min.

If the temperature of the ethylene / vinyl alcohol copolymer resin film after the lapse of 60 seconds after laminating on a metal material is not lower than the crystal melting start temperature (Ts), the properties of the film-coated metal sheet obtained are remarkably deteriorated. . Specifically, ethylene laminated to a metal material
Crystallization of the vinyl alcohol copolymer resin film progresses, processability decreases, the appearance of the film changes from transparent to milky white, and corrosion resistance after processing decreases.

A metal material laminated with an ethylene / vinyl alcohol copolymer resin film is mixed with a crystal melting start temperature (T
s) or lower, preferably 6 (Ts-20 ° C) or lower.
If you can not cool in less than 0 seconds,
By performing the treatment described below, crystallization of the ethylene / vinyl alcohol copolymer resin film can be suppressed.

That is, the melting point (Tm) to (Tm + 150 ° C.) of the ethylene / vinyl alcohol copolymer resin film
Laminate the ethylene / vinyl alcohol copolymer resin film on the surface of the metal material heated to the temperature of, and then reheat this metal material to a temperature above the melting point (Tm) and below the decomposition temperature of the ethylene / vinyl alcohol copolymer resin film. Immediately after heating or after holding for 10 minutes or less, a metal material laminated with an ethylene / vinyl alcohol copolymer resin film is heated to a temperature below the crystal melting start temperature (Ts) of the ethylene / vinyl alcohol copolymer resin film, preferably Is cooled to a temperature not higher than (Ts-20 ° C.) within 60 seconds. As a result, it suppresses crystallization of the ethylene / vinyl alcohol copolymer resin film, has sufficient gas barrier properties and is excellent in aroma retention, and is also excellent in processability, appearance and properties such as corrosion resistance after processing. It is possible to obtain a film-coated metal plate. If these processing conditions are not satisfied, the effect of suppressing the above-mentioned crystallization will not be sufficiently exerted. Also, when holding the metal material while reheating,
Even if the holding time is made longer than 10 minutes, the effect equivalent to that is not exhibited, and the energy is wasted.

Regarding the heating method of the metal material and the heating method of reheating the metal material after laminating the ethylene / vinyl alcohol copolymer resin film, especially if the surface temperature of the metal material can be within the above range. Although there is no limitation, the method by resistance heating and the method by induction heating are preferably applied from the viewpoint of producing the film-coated metal sheet of the present invention continuously and stably at a high speed. That is, these methods can raise the temperature of the metal material to a predetermined temperature in a short time of 1 to 20 seconds and the temperature control is easy. Other heating methods include, for example, an oven heating method and an infrared heating method. Although the productivity is poor, a laminating method using a hot press can be applied.

Various methods are conceivable as a method of rapidly cooling after laminating a metal material and an ethylene / vinyl alcohol copolymer resin film, for example, a method by water spraying, a method of immersing in water, A method using liquid nitrogen, a method of spraying cooled air, a method of using a cooling roll cooled by these, and the like are industrially suitable.

The film-coated metal sheet of the present invention has a processability,
Not only is it excellent in appearance and corrosion resistance after processing, but also has sufficient gas barrier properties and is excellent in aroma retention, and therefore, it is suitably used as a material for forming containers, particularly food containers. In particular, the film-coated can formed by molding the film-coated metal plate has excellent properties as a container for beverages, such as beer, where flavor is important. Further, the film-coated metal plate of the present invention can be preferably used as a lid material for a container. Film-coated can and manufacturing method thereof The film-coated can of the present invention is formed by molding the above-mentioned film-coated metal plate, and has an ethylene / vinyl alcohol copolymer resin film on at least the inner surface of the metal material. .

The film-coated can is manufactured by drawing the film-coated metal plate. The film-coated metal plate is usually used in the form of a disc blank, and is formed into a hollow cylindrical can by drawing the disc blank.

[0033] Here, aperture ratio in drawing is the diameter of the circular plate blank when D _0, the diameter of the can and d, expressed in (aperture ratio) = D ₀ / d, its value is 1 It should be 1 or more. If this draw ratio (D ₀ / d) is less than 1.1, the height for filling the contents particularly as a food container is insufficient and the food container does not function sufficiently.

In the film-coated can of the present invention, the side wall portion may be ironed after the drawing. The ironing process is a process of thinning the side wall of the can due to the stretching effect. By performing this ironing process, weight reduction is achieved as compared to a can of the same volume manufactured without performing the ironing process. In addition, the amount of the film-coated metal plate used can be reduced.

When squeezing is further performed after the squeezing ratio is 1.1 or more, the squeezing rate at the side wall of the can is determined by the type of metal material and the ethylene / vinyl laminated on the metal material. It is difficult to determine uniformly because it varies depending on the thickness of the alcohol copolymer resin film, the ethylene copolymerization ratio, etc., but in the side wall of the can, the following formula (1); Re = [(t ₀ −t ₁ ) / T ₀ ] × 100 (1) [In the formula (1), t ₀ represents the thickness of the film-covered metal plate at the bottom of the can, and t ₁ represents the thickness of the film-covered metal plate at the side wall of the can. Represents ] It is preferable that the total ironing rate (Re) defined by the above is in the range of 10 to 50% for one-step ironing and 30 to 85% for the overall ironing. Generally, if the total ironing ratio is less than 30%, the above-mentioned effects due to the ironing process may not be sufficiently exhibited. On the other hand, if it exceeds 85%, the strength may be insufficient or the can may not be molded.

Here, the gas barrier property of the ethylene / vinyl alcohol copolymer resin film constituting the film-coated metal plate is improved by stretching the side wall of the can by ironing. That is, the ironing process does not impair the gas barrier property of the ethylene / vinyl alcohol copolymer resin film.

This ironing can be performed by using an ironing tool consisting of a cylindrical punch and an annular die. In the ironing, it is preferable to use the following annular die.

That is, the working portion of the annular die comprises a bearing portion and an inclined portion for ironing. In the method for manufacturing a film-coated can of the present invention, the inclined portion has an inclination angle of 2 to 30. A circular die in the range of 2 to 20 degrees is used.

In the method for producing a film-coated can of the present invention, if the inclination angle of the annular die used is less than 2 degrees,
The contact area between the film-coated metal cup and the annular die obtained by drawing the film-coated metal plate at a drawing ratio of 1.1 or more increases the frictional force and increases the ironing stress. When reaches the breaking stress of the metal material, the side wall part is broken during the ironing process. On the other hand, when the inclination angle of the inclined portion of the annular die exceeds 30 degrees, the strain rate of deformation increases with respect to the constant punch speed, and the deformation resistance increases. In addition, the additional shearing force is increased and the deformation resistance is further increased. As a result, when the film coating is formed on the outer surface of the can as well, the film coating is likely to seize on the contact surface with the annular die, the film surface on the outer surface of the can is roughened, and the aesthetic appearance is deteriorated. When printing on a sheet, there is a problem that it causes ink bleeding.

In the method for producing a film-coated can of the present invention, at least ironing, preferably drawing and ironing are performed at a temperature range of 10 ° C. to the glass transition temperature (Tg) of the ethylene / vinyl alcohol copolymer resin film. It is desirable to do in. If this temperature is lower than 10 ° C., the workability of the ethylene / vinyl alcohol copolymer resin film of the film-coated metal plate may be lowered, and troubles such as breakage and peeling may occur. On the other hand, the glass transition temperature (T
If it exceeds g), the processability of the ethylene / vinyl alcohol copolymer resin film of the film-coated metal sheet is improved, but defects such as flaws are likely to occur on the surface of the film after processing, leading to deterioration of corrosion resistance. There is.

The film-coated can of the present invention produced as described above has a film made of an ethylene / vinyl alcohol copolymer resin film on at least the inner surface of the can. It is not only excellent, but also excellent in aroma retention, and is particularly suitably used as a container for beverages such as beer or foods in which flavor is an important factor.

[0042]

EXAMPLES Next, examples of the present invention will be shown to explain the present invention more specifically. Example 1 An aluminum plate (JIS A5052P H18, plate thickness 0.3 mm) having a phosphoric acid chromate treatment coating layer (coating amount; 20 mg / m @ 2 on each side as Cr) on both sides of the aluminum plate was heated at 250 ° C. by an infrared heating method. Non-stretched ethylene / vinyl alcohol copolymer resin film [made by Kuraray Co., Ltd., EVAL (type EF-F, ethylene copolymerization ratio 32 mol%), melting point 181 ° C. , Glass transition temperature 69
℃, crystallization temperature 161 ℃, decomposition temperature 280 ℃, thickness 15
μm] and then immediately cooled to 20 ° C. with water to obtain a film-coated can by drawing using a film-coated aluminum plate under the following molding conditions. <Molding conditions> (1) Blank diameter; 140 mm (2) Drawing condition; 1st drawing ratio; 1.61 Next, this film-coated can was subjected to a film adhesion test and a water flavor test under the following conditions. The results are shown in Tables 1 and 2. <Film adhesion test> 17 after degreasing and cleaning the film-coated can
After drying at 5 ° C for 10 minutes, the film adhesion test was performed on the side wall of the film-coated can according to the crosscut tape method of JIS K5400.

(1) Clearance between cuts; 1 mm (2) Number of squares; 100 <Water flavor test> 17 after degreasing and cleaning the film-coated can
It was dried at 5 ° C for 10 minutes, filled with activated carbon-treated water to a height of 90% of the can height, kept at 100 ° C for 30 minutes and cooled at room temperature, and then a sensory test was conducted on the activated carbon-treated water in the can. It was

Further, with respect to the film-coated can, the sorption amount of the flavor component to the resin film on the inner surface of the can was measured under the following conditions (sorption test), and the beer cold turbidity stability test under the following conditions. Was done. The results are shown in Tables 2 and 3. <Sorption test> (1) Model flavor solution; 2.5 ppm ethyl acetate / 5% ethanol aqueous solution (2) Sorption condition; After washing the film-coated can with water and drying, after filling with 350 ml of the above model flavor solution , The can lid was seamed. This model flavor solution-filled film-coated can was stored at a constant temperature of 25 ° C. for 2 weeks, and after discarding the content liquid, it was washed with water and the flavor adsorbed on the inner film was extracted with diethyl ether. The extracted flavor was quantified by gas chromatography. The unit of data obtained is 1 ppm per can.
The flavor of the concentration was indicated by the number of μg adsorbed on the resin film on the inner surface of the can. <Cold turbidity stability test> (1) Test liquid; beer (2) Storage test conditions; 0 ° C after storage at 40 ° C for 2 weeks
Cool for 25 hours.

(3) Apparatus used: UKMI type haze meter manufactured by Radiometer

[0046]

[Table 1]

[0047]

[Table 2]

[0048]

[Table 3] (Study of Results) As is clear from Tables 1 to 3, the adhesion of the ethylene / vinyl alcohol copolymer resin film to the metal material is good, and the water flavor test, sorption test, and cold turbidity stability of beer are stable. It was confirmed that the test results were all good. Example 2 In Example 1, the drawing condition in the molding conditions was set to 1
1st aperture ratio: 1.61, from 1st aperture ratio: 1.61
Example 2 except that the 2nd aperture ratio was changed to 1.32.
The film-coated can was molded in the same manner as in 1. and the obtained film-coated can was subjected to the film adhesion test, the water flavor test, the sorption test and the beer cold turbidity stability test in the same manner as in Example 1. The results are shown in Tables 1 to 3, and all were good. Example 3 An aluminum plate (JIS A3004P H19, plate thickness 0.3 mm) having phosphoric acid chromate treatment coating layers (coating amount; 15 mg / m ^{2 on each} side as Cr) on both sides of the aluminum plate was heated at 220 ° C. by an infrared heating method. Of the non-stretched ethylene / vinyl alcohol copolymer resin film [manufactured by Kuraray Co., Ltd., EVAL (type EF-F, ethylene copolymerization ratio 32 mol%), melting point 181. ℃, glass transition temperature 69
℃, crystallization temperature 161 ℃, decomposition temperature 280 ℃, thickness 15
μm], and then the film-coated aluminum plate was heated to a plate temperature of 200 ° C., heated, held for 1 minute, and then water-cooled to 20 ° C. A film-coated can was obtained by performing drawing and ironing under the conditions. <Molding conditions> (1) Blank diameter; 140 mm (2) Drawing condition; 1st drawing ratio; 1.61, 2nd drawing ratio; 1.32 (3) Ironing punch (cylindrical punch) diameter: 66.045
mm (4) Ironing die (annular die) Tilt angle of inclined part: 8 ° (5) Total ironing rate: 65% (6) Ironing processing temperature (coolant temperature): 40 ° C About the film-coated can thus obtained A film adhesion test, a water flavor test, a sorption test and a beer cold turbidity test were conducted in the same manner as in Example 1. The results are shown in Tables 1 to 3, and all were good. Example 4 On both surfaces of a mild steel plate (Temper T-1, plate thickness 0.3 mm), a chromium hydrated oxide layer (coating amount; 16 mg / m ² as Cr on each side) was formed on both surfaces, and a metallic chromium layer (coating amount was formed on the lower surface) ; C
A steel sheet having 100 mg / m ² per side as r was heated to a sheet temperature of 200 ° C. by an infrared heating method, and an unstretched ethylene / vinyl alcohol copolymer resin film [made by Kuraray Co., Ltd.] was formed on both sides of the heated steel sheet. , "EVAL" (type EF-E, ethylene copolymerization ratio 44 mol%), melting point 1
64 ° C, glass transition temperature 55 ° C, crystallization temperature 142 ° C,
Decomposition temperature: 280 ° C., thickness: 25 μm], then the laminated steel plate is heated to a plate temperature of 180 ° C., held for 1 minute after heating, and then water-cooled to 20 ° C. to obtain a film-coated steel plate, A film-coated can was obtained in the same manner as in Example 1.

In the film-coated can thus obtained,
Then, a film adhesion test was conducted in the same manner as in Example 1 above.
Water flavor test, sorption test and cold cloudiness of beer
I did a qualitative matter. The results are shown in Tables 1 to 3.
And all were good. Example 5 In Example 3, the aluminum plate was coated with
Biaxially stretched ethylene / vinyl alcohol copolymer
Resin film [made by Kuraray Co., Ltd., "Eval" (type
EF-XL, ethylene copolymerization ratio 32 mol%), melting point 1
81 ° C., glass transition temperature 69 ° C., crystallization temperature 161 ° C.,
Decomposition temperature 280 ° C, thickness 15 μm]
A film-coated can was obtained in the same manner as in Example 3.

With respect to this film-coated can, in the same manner as in Example 1, a film adhesion test, a water flavor test,
Sorption tests and beer cold turbidity stability tests were performed.
The results are shown in Tables 1 to 3, and all were good. Example 6 In Example 3, the ironing dies (annular dies) used for ironing were selected from those having an inclination angle of 8 °.
In addition to changing the degree to 65 °, the total ironing rate is changed from 65% to 4
A film-coated can was obtained in the same manner as in Example 3 except that the content was changed to 0%.

With respect to this film-coated can, in the same manner as in Example 1 above, a film adhesion test, a water flavor test,
Sorption tests and beer cold turbidity stability tests were performed.
The results are shown in Tables 1 to 3, and all were good. Example 7 In Example 3, the ironing dies (annular dies) used for the ironing process were 3 ° from the inclined part having an inclination angle of 8 °.
And change the total ironing rate from 65% to 75
%, Ironing temperature (coolant temperature) from 40 ℃ to 2
A film-coated can was obtained in the same manner as in Example 3 except that the temperature was changed to 0 ° C.

With respect to this film-coated can, in the same manner as in Example 1 above, a film adhesion test, a water flavor test,
Sorption tests and beer cold turbidity stability tests were performed.
The results are shown in Tables 1 to 3, and all were good. Comparative Example 1 An aluminum plate (JIS A5052P H18, plate thickness 0.3 mm) having a phosphoric acid chromate treatment coating layer (coating amount; 20 mg / m ^{2 on each} side as Cr) on both sides of the aluminum plate was subjected to infrared heating at 150 ° C. (Comparative 1) or 350 (Comparative 2), the unheated ethylene / vinyl alcohol copolymer resin film [made by Kuraray Co., Ltd., EVAL (Type EF-F, Ethylene copolymerization ratio 32 mol%), melting point 181 ° C., glass transition temperature 69 ° C., crystallization temperature 161 ° C., decomposition temperature 280 ° C., thickness 15 μm], and then immediately cooled to 20 ° C. with water to form film-coated aluminum. I got a plate.

The obtained film-coated aluminum plate was
In Comparative Example 1, the adhesion between the aluminum plate and the copolymer resin film is insufficient and it is not suitable for molding.
In this case, the copolymer resin film turned pale yellow and was thermally deteriorated. The results are shown in Tables 1 to 3. Comparative Example 2 An aluminum plate (JIS A3004P H19, plate thickness 0.3 mm) having a phosphoric acid chromate treatment coating layer (coating amount; 15 mg / m ^{2 on each} side as Cr) on both sides of the aluminum plate was heated at 220 ° C. by an infrared heating method. Of the non-stretched ethylene / vinyl alcohol copolymer resin film [manufactured by Kuraray Co., Ltd., EVAL (type EF-F, ethylene copolymerization ratio 32 mol%), melting point 181. ℃, glass transition temperature 69
℃, crystallization temperature 161 ℃, decomposition temperature 280 ℃, thickness 15
μm], and then held at 160 ° C. for 2 minutes and then cooled to 20 ° C. without cooling with water, using a film-coated aluminum plate, and drawing under the same molding conditions as in Example 3 above. And ironed. The results are shown in Tables 1 to 3, and it was impossible to mold the can. Comparative Example 3 An aluminum plate (JIS A3004P H19, plate thickness 0.3 mm) having a phosphoric acid chromate treatment coating layer (coating amount; 15 mg / m ^{2 on each} side as Cr) on both sides of the aluminum plate was heated at 220 ° C. by an infrared heating method. Of the non-stretched ethylene / vinyl alcohol copolymer resin film [manufactured by Kuraray Co., Ltd., EVAL (type EF-F, ethylene copolymerization ratio 32 mol%), melting point 181. ℃, glass transition temperature 69
℃, crystallization temperature 161 ℃, decomposition temperature 280 ℃, thickness 15
μm], and then the laminated aluminum metal plate is heated to 160 ° C. (comparative 4) or 300 ° C.
Using the film-coated metal plate obtained by heating to the plate temperature of (Comparative 5), holding for 1 minute after heating, and then water cooling to 20 ° C., under the same molding conditions as in Example 3, drawing and ironing I went. The results are shown in Table 1 as a comparison 4 of Table 3,
The results are as shown in Comparative Example 5. The Comparative Example 4 was incapable of forming a can, and the Comparative Example 5 was unsuitable as a container due to cracking of the film. Comparative Example 4 On both surfaces of a mild steel plate (Temper T-1, plate thickness 0.3 mm), an upper layer of hydrated chromium oxide layer (coating amount; 16 mg / m ² as Cr on one side) and a lower layer of metallic chromium layer (coating amount). ; C
A steel sheet having 100 mg / m ² per side as r was heated to a plate temperature of 250 ° C. by an infrared heating method, and an unstretched ethylene / vinyl alcohol copolymer resin film (ethylene copolymerization ratio 10 Mol%, melting point 220 ° C., glass transition temperature 75 ° C., crystallization temperature 185
C., thickness 25 .mu.m), then the laminated steel sheet was heated to a plate temperature of 240.degree. C., held for 1 minute after heating, and then water-cooled to 20.degree. Drawing was performed under the same molding conditions as in 1 to obtain a film-coated can.

With respect to this film-coated can, in the same manner as in Example 1, a film adhesion test, a water flavor test,
Sorption tests and beer cold turbidity stability tests were performed.
The results are as shown in Tables 1 to 3, and the sorption amount of the flavor component was large and the fragrance retaining property was poor. Comparative Example 5 On both surfaces of a mild steel plate (Temper T-1, plate thickness 0.3 mm), a hydrated chromium oxide layer (coating amount; 16 mg / m ² as Cr on each side) was formed as an upper layer, and a metallic chromium layer (coating amount was formed as a lower layer). ; C
A steel sheet having 100 mg / m ² per side as r is heated to a sheet temperature of 150 ° C. by an infrared heating method, and an unstretched ethylene / vinyl alcohol copolymer resin film (ethylene copolymerization ratio 80 Mol%, melting point 105 ° C., glass transition temperature 35 ° C., thickness 25 μm), and then the laminated steel plate is heated to a plate temperature of 130 ° C., held for 1 minute after heating, and then cooled to 20 ° C. with water. Using the obtained film-coated steel sheet, drawing was performed under the same molding conditions as in Example 1 to obtain a film-coated can.

With respect to this film-coated can, the film adhesion test, the water flavor test, and the
Sorption tests and beer cold turbidity stability tests were performed.
The results are as shown in Tables 1 to 3, and the sorption amount of the flavor component was large and the fragrance retaining property was poor. Comparative Example 6 In Example 3, the ironing dies (annular dies) used for the ironing process were changed from those having an inclination angle of 8 ° to 35.
In addition to changing the degree to 65 °, the total ironing rate is changed from 65% to 3
A film-coated can was obtained in the same manner as in Example 3 except that the content was changed to 2%.

This film-coated can was unsuitable as a container because the film surface on the outer surface of the can became a rough surface.
The results are shown in Tables 1 to 3. Comparative Example 7 In Example 3, the ironing dies (annular dies) used for the ironing process were changed from those having an inclination angle of 8 ° to 0 °.
A film-coated can was obtained in the same manner as in Example 3 except that the above was used.

This film-coated can was unsuitable as a container because the film surface on the outer surface of the can became a rough surface.
The results are shown in Tables 1 to 3. Comparative Example 8 In Example 3, the ironing dies (annular dies) used in the ironing process were 3 ° from those having an inclination angle of 8 °.
The total ironing rate from 65% to 87
%, And drawing and ironing were carried out under the same molding conditions as in Example 3 above.

The results are shown in Tables 1 to 3,
It was impossible to mold the can. Comparative Example 9 The same molding conditions as in Example 3 were used except that the ironing temperature (coolant temperature) in Example 3 was changed from 40 ° C. to 5 ° C. (Comparison 11) or 80 ° C. (Comparison 12). Was drawn and ironed. as a result,
In Comparative Example 11, the ethylene / vinyl alcohol copolymer resin film was cracked, and in Comparative Example 12, a film-like defect was generated on the film surface, which was not suitable as a container. The results are shown in Tables 1 to 3. Comparative Example 10 An aluminum plate (JIS A3004P H19, plate thickness 0.3 mm) having phosphoric acid chromate treatment coating layers (coating amount; 15 mg / m ^{2 on each} side as Cr) on both sides of the aluminum plate was heated to 300 ° C. by an infrared heating method. Of the polyethylene aluminum terephthalate film (melting point 260 ° C., glass transition temperature 70 ° C., decomposition temperature 330 ° C., thickness 15 μm) on both sides of the heated aluminum plate.
Was used, and then the laminated aluminum plate was heated to a plate temperature of 270 ° C., heated for 1 minute and then cooled to 20 ° C. with water, and the film-coated aluminum plate was used. Drawing and ironing were performed under molding conditions to obtain a film-coated can.

With respect to this film-coated can, in the same manner as in Example 1, a film adhesion test, a water flavor test,
Sorption tests and beer cold turbidity stability tests were performed.
The results are as shown in Tables 1 to 3, and the sorption amount of the flavor component was large and the fragrance retaining property was poor. Comparative Example 11 Using a rolled aluminum plate (JIS A3004P H19, plate thickness 0.3 mm), drawing and ironing were performed under the same molding conditions as in Example 3 to obtain a drawn and ironed can. This squeezed and ironed can is degreased and washed, followed by phosphoric acid chromate treatment, and then an epoxy-based can inner surface coating is applied to the inner surface of the can to a dry film thickness of 5 μm, and dried at 205 ° C. for 2 minutes. To obtain a painted can.

A film adhesion test was conducted on the coated can under the following conditions. <Film adhesion test> JI
A film adhesion test was performed according to the cross-cut tape method of SK5400. The results are shown in Table 2.

Further, a water flavor test, a sorption test and a cold turbidity stability test of beer were conducted in the same manner as in Example 1. The results are as shown in Tables 1 to 3, and the sorption amount of the flavor component was large and the fragrance retaining property was poor.

[0062]

As described above in detail, according to the present invention, an ethylene / vinyl alcohol copolymer resin film is used as a coating material for a metal material, and the laminating conditions and the molding conditions for the film coating material are regulated. Because it was configured,
Adhesiveness of resin film, corrosion resistance, and appearance characteristics required as various container materials are provided, and when food containers are used, the amount of flavor components sorbed is small and it also has excellent aroma retention, Provided are a film-coated metal sheet having properties suitable as a packaging material for various packaging materials, particularly beverages and other contents in which flavor is important, a film-coated can having such advantages, and a method for producing the same.

Claims (11)

[Claims] 1. A film-covered metal plate, characterized in that an ethylene / vinyl alcohol copolymer resin film is adhered to at least the inner surface of the can of the metal material. 2. The film-coated metal plate according to claim 1, wherein the metal material is aluminum, an aluminum alloy or steel. 3. The film-coated metal plate according to claim 1, wherein the metal material is aluminum or an aluminum alloy, and a phosphoric acid chromate treatment film is provided on the surface of the metal material. 4. The film-coated metal plate according to claim 1, wherein the metal material is steel, and a tin plating film or an electrolytic chromic acid treatment film is provided on the surface of the metal material. 5. The ethylene / vinyl alcohol copolymer resin film has an ethylene copolymerization ratio of 20 to 70 mol%.
The film-coated metal plate according to claim 1, wherein 6. The ethylene / vinyl alcohol copolymer resin film is laminated on the metal material heated to a temperature of the melting point (Tm) to (Tm + 150 ° C.) of the ethylene / vinyl alcohol copolymer resin film, and the laminate. The film-coated metal plate according to any one of claims 1 to 5, wherein the metal material is rapidly cooled to a temperature not higher than the crystal melting start temperature (Ts) of the copolymer resin film. 7. The ethylene / vinyl alcohol copolymer resin film is laminated with the ethylene / vinyl alcohol copolymer resin film on the metal material heated to a temperature of melting point (Tm) to (Tm + 150 ° C.) of the ethylene / vinyl alcohol copolymer resin film. The above-mentioned metal material is heated to a temperature not lower than the melting point (Tm) and not higher than the decomposition temperature of the copolymer resin film and held immediately after the heating or within 10 minutes, and then the crystal melting start temperature (Ts) of the copolymer resin film. The film-coated metal plate according to any one of claims 1 to 5, which is rapidly cooled to the following temperature. 8. A film-coated metal plate, in which an ethylene / vinyl alcohol copolymer resin film is adhered to at least the inner surface of a can of a metal material, is drawn at a drawing ratio of 1.1 or more. Film coated cans. 9. Further, in the side wall portion of the can, the following formula (1); Re = [(t ₀ −t ₁ ) / t ₀ ] × 100 (1) [where, in the formula (1), t ₀ Represents the thickness of the film-covered metal plate at the bottom of the can, and t ₁ represents the thickness of the film-covered metal plate at the side wall of the can. ] The film-coated can according to claim 8, which is thinned so that the total ironing ratio (Re) defined by the above is 30 to 85%. 10. A film-covered metal plate, in which an ethylene / vinyl alcohol copolymer resin film is adhered to at least the inner surface of a can of a metal material, and a drawing ratio of 1.1.
The film-coated can according to claim 9, which is drawn and then ironed within a range of 10 ° C to the glass transition temperature (Tg) of the copolymer resin film. 11. A film-coated metal plate in which an ethylene / vinyl alcohol copolymer resin film is adhered to at least a surface to be an inner surface of a can, and the film-coated metal plate is drawn at a drawing ratio of 1.1 or more. , The acting part is
Manufacture of a film-coated can characterized by comprising an annular die having an inclined portion and a bearing portion for performing ironing and having an inclination angle of the inclined portion of 2 to 30 degrees. Method.