JP2000318088A - Film laminated metal plate and metal can - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve workability and to prevent an oxidation and a decomposition of a content by laminating a film made of a polyester containing an aromatic dicarboxylic acid component and a glycol component as main components and containing a polymer oxygen absorbent in the polyester on a surface of a metal plate. SOLUTION: A film made of a polyester containing an aromatic dicarboxylic acid component and a glycol component as main components and containing a polymer oxygen absorbent in the polyester is laminated on an at least one surface of a metal plate. Then, as the absorbent, a polymer compound having a double bond in a molecular is selected. As an oxygen absorbing catalyst, a transition metal is contained in the film, and the catalyst is selected from Co, Fe, Ni or the like. An ultraviolet sensitizer is contained in the film, and selected from a silica, an alumina or a zeolite.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal plate on which a polyester film is laminated, and a metal can formed by forming the laminated metal plate into a can shape. Specifically, it has excellent workability when making cans through deformation processing steps such as squeezing and ironing, and when filling contents such as beverages, prevents oxidation and decay of the contents, The present invention relates to a film-laminated metal plate and a metal can that can maintain flavor for a long period of time.

[0002]

2. Description of the Related Art Conventionally, in a can-making process for metal cans, there have been proposed methods for preventing corrosion of metal plates such as tinplate, tin-free steel, rotin steel, and aluminum, and preventing odor from being transferred to the contents. I have been painting one or more times. However, performing such multiple coatings not only complicates the baking process but also requires a great deal of time. Further, since a large amount of solvent is discharged at the time of coating, there are environmental and sanitary problems. More recently, bisphenol A contained in paints
Dissolution of endocrine disrupters such as is a problem.

In order to solve these problems, attempts have been made to laminate a thermoplastic resin film on a metal plate. In particular, a laminate obtained by laminating a polyester film on a metal plate has attracted attention in terms of heat resistance and hygiene. ing. One example is a method of laminating a polyester film on a metal plate via an adhesive layer and using it for can making (Japanese Patent Publication Sho 62-6).
No. 1427) or a method of laminating a polyester film on a metal plate without using an adhesive and using it for a can (Japanese Patent Publication No. 60-47103).

[0004]

However, in the case of a two-piece can which has processing steps such as drawing and ironing at the time of can making, these methods produce pinholes, cracks, peeling, etc. under severe processing conditions. It has been found that problems such as corrosion of the metal plate surface occur. In addition, if the conditions for can making are relaxed to avoid these problems, there are problems such as a decrease in productivity and an increase in cost.

Japanese Patent Application Laid-Open No. 61-149340 discloses that a biaxially oriented polyester film is laminated on a metal plate heated to a temperature not lower than the melting point of the biaxially oriented polyester film and then quenched so that only the adhesive layer is unoriented. Attempts have been made to solve the above problem by using a polyester resin layer. In addition, JP-A-2-501638 discloses that when a polyester film is laminated on a surface of a metal plate, the metal plate is heated so that the temperature of the outer surface of the polyester film becomes lower than its melting point. And then reheating to a temperature equal to or higher than the melting point of the polyester, maintaining the temperature, and then rapidly cooling to a temperature equal to or lower than the glass transition point of the polyester to amorphize the entire film layer. However, the non-crystallized film absorbs the scent of the contents and may impair the flavor of the contents.

On the other hand, it is generally known that the cause of the odor of canned foods and the like is oxidative deterioration of the contents due to oxygen present inside. For example, in the case of beer, when brewing or filling in a bottle or can, the beer oxidizes and changes its taste due to oxygen that has penetrated into the contents or remained in the head space, and it is said that about 6 months is the expiration date. In the case of dry foods and the like, there is an example in which a small bag of an oxygen absorbent is added to the food package, but a method of adding the oxygen absorbent to the packaging of liquid food such as beer has not yet been known. The oxygen absorber generally includes an inorganic compound and an organic compound. As an oxygen absorber of an inorganic compound, a compound obtained by adding an oxidation promoter to a metal element such as Fe is known. Examples of organic compound oxygen absorbers include hindered phenols such as BHT, vitamin C, vitamin E, organic phosphorus compounds, gallic acid, pyrogallol,
There are drying oils such as linseed oil, tung oil, dehydrogenated castor oil, and lacquer. These low molecular organic oxygen absorbents cannot be used due to problems such as a low absorption rate, a low absorption amount, unsanitary, expensive, and off-flavor generation.

In view of such a background, the present invention has excellent workability when laminating on a metal plate and then carrying out a deforming process such as drawing and ironing, and is filled with contents such as beverages. In this case, it is an object of the present invention to provide a film-laminated metal plate and a laminated metal can using the same, which can prevent the contents from being oxidized and decomposed and can maintain the flavor of the contents for a long period of time.

[0008]

The film-laminated metal plate and the film-laminated metal can which can solve the above problems are as follows. 1. A film-laminated metal plate comprising a polyester containing an aromatic dicarboxylic acid component and a glycol component as main components, and a film containing a high-molecular oxygen absorbent in the polyester is laminated on at least one surface of the metal plate. 2. 2. The film-laminated metal plate according to the above item 1, wherein the high molecular oxygen absorbent contained in the laminated film is a high molecular compound having a double bond in the molecule. 3. 3. The film-laminated metal plate according to the above item 1 or 2, wherein the high molecular oxygen absorbent contained in the laminated film is polybutadiene diol. 4. 4. The film-laminated metal plate according to any one of the above 1 to 3, wherein the laminated film contains a transition metal as an oxygen absorbing catalyst. 5. Wherein the transition metal is at least one selected from Co, Fe, Ni, Mn, and Cu.
The film-laminated metal plate according to the above. 6. 6. The film-laminated metal plate according to any one of the above 1 to 5, wherein the laminated film contains an ultraviolet sensitizer. 7. 7. The film-laminated metal plate according to the item 6, wherein the ultraviolet sensitizer is at least one selected from benzophenone and a derivative thereof. 8. The film-laminated metal plate according to any one of the above 1 to 7, wherein the laminated film contains porous inorganic particles. 9. 9. The film-laminated metal plate according to the above item 8, wherein the porous inorganic particles are at least one selected from silica, alumina and zeolite. 10. 10. The film-laminated metal plate according to any one of the above items 1 to 9, wherein the laminated film contains an antioxidant. 11. 11. The film-laminated metal plate according to any one of the above items 1 to 10, wherein another resin having no oxygen absorbing property is laminated on the laminated film. 12. 12. The film-laminated metal plate according to any one of the above items 1 to 11, wherein the metal plate is made of a material selected from the group consisting of aluminum, steel or an alloy containing these as a main component. 13. A film-laminated metal can manufactured using the film-laminated metal plate of any one of 1 to 12 above.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The main components of the polyester constituting the laminate film in the present invention are preferably terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, etc. as an acid component, and ethylene glycol, , 4-butanediol and the like are preferred. In particular, polyethylene terephthalate is preferred in terms of impact resistance, heat resistance, and fragrance retention.

The polyester may contain a copolymer component in order to achieve the object of the present invention. The copolymer component may be either an acid component or a diol component.
As the acid component, isophthalic acid, orthophthalic acid, 2,
Aromatic dicarboxylic acids such as 6-naphthalenedicarboxylic acid,
Examples thereof include aliphatic dicarboxylic acids such as adipic acid, azelaic acid, and sebacic acid, and alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid. Further, as the diol component, 1,4-butanediol, diethylene glycol,
Examples include triethylene glycol, neopentyl glycol, cyclohexane dimethanol, and the like. These can be used alone or in combination of two or more. The proportion of the copolymer component is preferably 30 mol% or less based on the total number of moles of the acid component. 30 mol% of copolymerization component
If it exceeds, not only the impact resistance and the heat resistance are deteriorated, but also a problem occurs in the fragrance retention, which is not preferable.

The method for producing the polyester resin constituting the laminate film in the present invention is carried out by using a known method such as a conventional transesterification method or a direct polymerization method.
It is preferable to synthesize by a direct polymerization method from the viewpoint of fragrance retention. In addition, by reducing acetaldehydes by a method such as solid phase polymerization, the fragrance retention can be further improved.
If necessary, an antioxidant, an ultraviolet absorber, a heat stabilizer, an antistatic agent, a pigment, and the like may be added.

The oxygen absorber generally includes an inorganic compound and an organic compound. As an oxygen absorber of an inorganic compound, those obtained by adding an oxidation promoter to a metal element such as Fe are known. Examples of organic compound oxygen absorbers include hindered phenols such as BHT, vitamin C, vitamin E, organic phosphorus compounds, gallic acid, pyrogallol,
There are drying oils such as linseed oil, tung oil, dehydrogenated castor oil, and lacquer. However, these low molecular organic oxygen absorbers
It cannot be used due to problems such as a low absorption rate, a small absorption amount, unsanitary, expensive, and off-flavor.

As the high molecular oxygen absorbent of the present invention, any high molecular compound having a C ＝ C double bond in the molecule can be used. For example, polybutadiene, polyisoprene, butadiene / isoprene copolymer, etc. exhibit excellent performance as the oxygen absorbent of the present invention. Polybutadiene includes 1,2-polybutadiene and 1,4-polybutadiene, and 1,2-polybutadiene is characterized by a higher oxygen absorption rate. Either of these may be used, but when importance is placed on oxygen absorption at low temperatures,
4-Polybutadiene is preferred. Polyisoprene is cis-1,4-polyisoprene (the main component of natural rubber)
And trans-1,4-polyisoprene (gutta percha), either of which is acceptable. SB (styrene / butadiene) copolymer can also be used as an oxygen absorbent. In this case, the block copolymer has a better oxygen absorbing ability than the random copolymer, and the greater the butadiene content, the greater the oxygen absorption, and the greater the styrene content, the better the moldability.

A food packaging container using a high-molecular oxygen absorbent that has a short induction period until the start of oxygen absorption starts oxygen absorption immediately after packaging, so that the oxygen concentration in the food can be effectively reduced. However, oxygen is absorbed even during the stock period before packaging the food, so that the oxygen absorption life is short.
Food packaging containers using a high-molecular oxygen absorbent that has a long induction period until the start of oxygen absorption can be stocked for a long time before use, but have a relatively small oxygen absorption capacity. By adding one or more transition metals and an ultraviolet sensitizer to the polymer oxygen absorber of the present invention, oxygen absorption can be started immediately upon irradiation with ultraviolet light without oxygen absorption during the stock period, For example, it is possible to laminate a film containing a high molecular oxygen absorbent on a metal plate, irradiate the film with ultraviolet light, and then immediately make it into a metal can.

As the transition metal used as the oxygen-absorbing catalyst, Co, Mn, Ni, Cu and Fe are preferred in terms of catalytic activity, and Co is most preferred because of its catalytic activity. C
As the counter ion of o, neodecanoate and 2-ethylhexaate are most suitable. As the ultraviolet sensitizer, benzophenone or a derivative thereof is suitable from the viewpoint of compatibility with a polymer compound, and among them, 4-allyloxybenzophenone is particularly suitable because of its good compatibility with a polymer compound.

The oxygen absorption induction period can be extended by adding an antioxidant such as BHT or a phosphorus compound to the high molecular oxygen absorbent of the present invention. Examples of the added antioxidant include 2,6-di (t-butyl) -4-methylphenol (BHT), triphenylphosphite, and the like, but are not limited thereto, and known antioxidants are used. Can be used. Other examples of the polymer oxygen absorbent of the present invention include polyolefins such as polypropylene (PP) containing tertiary hydrogen. Polypropylene containing a large amount of tertiary hydrogen starts absorbing oxygen in the presence of Co or an ultraviolet sensitizer, and is oxidized to generate low molecular weight volatile aldehydes, ketones, and carboxylic acids. Since low molecular weight volatiles such as aldehydes, ketones, and carboxylic acids generated here have a bad smell, the bad smell can be adsorbed by adding porous inorganic particles such as amorphous silica, alumina and zeolite.

Other examples of the high molecular oxygen absorbent of the present invention include a high molecular compound in which hydrogen is bonded to carbon adjacent to a carbonyl group, that is, a polymer having α hydrogen. Examples of the polymer having an α hydrogen include:
There are polyesters made from aliphatic dicarboxylic acids.
The number of carbon atoms in the aliphatic chain of the aliphatic dicarboxylic acid is preferably 2-10. A typical example is a polyester produced by a condensation reaction between hydroxyquinone diacetate and succinic acid. The oxidation reaction of such a high molecular oxygen absorbent is accelerated when a cobalt compound is present. The oxidation reaction is also accelerated by the magnesium compound.

Further, there may be mentioned a high-molecular oxygen absorbent containing a cobalt compound in polyamide and polyurethane made from meta-xylylenediamine. The high molecular oxygen absorbent containing cobalt in polymetaxylylenediaminoadipate (MXD6), which is produced by the condensation reaction of metaxylylenediamine and adipic acid, depends on the water content because the water triggers the oxidation reaction. The induction period to start oxygen absorption is different. By adding peroxide, ultraviolet sensitizer and other organic compounds together with cobalt to the polymer compound, oxygen absorption rate, oxygen absorption amount,
It is effective to control the length of the induction period.

The most preferred form of the high molecular oxygen absorbent of the present invention and the high molecular compound using the same is a polyester containing polybutadienediol in the molecule and having butadienediol bonded to the terminal of the polyester molecule. . As the polybutadiene diol contained as the oxygen absorbent, a molecular weight in the range of 1,000 to 3,000 is excellent in oxygen absorption capacity and suitable.

In this case, the amount of polybutadiene diol copolymerized with the polyester is preferably 1 to 12% by weight, more preferably 2 to 6% by weight. In this case, a part of the polybutadiene diol contained in the polyester is bonded to the polyester, whereby the compatibility between the polyester and the polybutadiene diol is improved, and a fine dispersed structure is formed. If it is less than 1% by weight, the oxygen absorbing ability is low, and if it exceeds 12% by weight, the transparency is poor.
However, when the film-laminated metal plate and the metal can using the same are used on the inner surface side of the container as in the present invention, transparency often does not matter, and the content can be 12% by weight or more.

In the present invention, the method for incorporating the above-mentioned oxygen absorbent into the polymer compound is not particularly limited.
A method in which a polymer compound, an oxygen absorber, other additives such as a transition metal catalyst, and an ultraviolet sensitizer are simultaneously added by a reactive extruder and melt-extruded is preferable. Similarly, in the case where polybutadiene diol is copolymerized with polyester, extrusion is performed in a range of 260 ° C. to 270 ° C. under a nitrogen stream by a reactive extruder. Extrusion reduces the degree of polymerization of the polyester and decreases physical properties. Therefore, it is preferable to use a vacuum vent type extruder. The obtained oxygen-absorbing polyester has at least IV of 0.5 to form a film.
Or more, and preferably IV is 0.6
That is all. Further, Tg needs to be 50 ° C. or higher, and preferably Tg is 60 ° C. or higher.

Next, as a method for producing a metal plate laminating film of the present invention using the obtained polyester, a resin melted by an extruder is extruded into a tube shape using a circular die, and the internal and external air pressures are extruded. There are an inflation method in which the resin is expanded by a difference, a method in which a resin melted by an extruder is extruded into a sheet shape using a T-die, and then a method of simultaneously or sequentially biaxially stretching, a method of only uniaxially stretching, or a method of not stretching. However, a method by biaxial stretching is preferred. For example, the polyester resin is dried, melted using an extruder, discharged from a T-die die and cooled on a cooling drum to obtain an unstretched film. At this time, T
It is preferable to dispose a polymer filter having an appropriate pore size as needed in the melt line immediately before the die to crush and remove coarse particles. Subsequently, the film is heated to 60 to 120 ° C. using a heating roll and stretched 2 to 6 times between two or more rolls having different rotation speeds. Further, the film was introduced into a tenter,
Stretched 2 to 6 times in the horizontal direction, and subsequently 120 to 24
A biaxially oriented film is obtained by relaxation and heat treatment at 0 ° C.

The thickness of the polyester film for lamination of the present invention varies depending on the type of the desired can, the purpose and the type and thickness of the metal plate used, and the type of the drawing / ironing tool, but is in the range of 7 to 50 μm. Is preferred. More preferably, it is 10 to 25 μm. 7μ film thickness
If it is less than m, a laminated metal sheet having sufficient workability and corrosion resistance cannot be obtained. Also, if the film thickness is 50
If it exceeds μm, the characteristics of the film itself will not be able to follow severe processing deformation during drawing and ironing, and not only will not be able to obtain sufficient workability, but also disadvantages in productivity and cost will not be negligible. Not preferred.

In order to control oxygen absorption, oxygen barrier, oxygen permeability, adhesiveness, fragrance retention, etc., at least one surface of the oxygen-absorbing polyester layer is provided on the laminating film of the present invention. Can be laminated. Other polymers include nylon, polyethylene, polypropylene, polyester, polyvinyl alcohol and the like. Examples of the laminated polyester film for lamination include a three-layer film of an oxygen-absorbing polyester layer / a polyester layer / a heat-adhesive low-melting polyester layer, and a three-layer film of a polyester layer / an oxygen-absorbing polyester layer / a heat-adhesive low-melting polyester layer. Examples include a film, a two-layer film of an oxygen-absorbing polyester layer / a heat-adhesive low-melting polyester layer, and a two-layer film of an oxygen-absorbing polyester layer / polyester layer, but are not particularly limited thereto. Examples of the method of laminating the films include a method by melt co-extrusion, a method by lamination such as dry lamination, wet lamination, extrusion lamination, and thermal lamination, and a known method can be selected. In addition, a method of laminating the films in advance and laminating the laminated films on a metal plate, and a method of laminating a plurality of films on the metal plate simultaneously or in several times are also possible. When the other polymer which does not contain an oxygen absorbent at the same time as laminating the film is polyester, a method of laminating by melt co-extrusion at the time of film formation is preferable.

The film of the present invention may contain known inert particles for the purpose of imparting lubricity as required. When the film is a single-layer polyester film, the inert particles are contained in the polyester. When the film is a multilayer, the inert particles are contained in the outermost polymer. The type of the inert particles may be organic or inorganic. Examples of the inorganic particles include metal oxides such as silica, alumina and titanium oxide and their composite oxides, natural and synthetic oxides such as kaolin, talc, zeolite and mullite, and difficulties such as calcium carbonate and barium sulfate. It can be selected from soluble inorganic metal salts and the like. Examples of the organic particles include crosslinked polystyrene particles, organic particles such as silicone particles, calcium, magnesium, and a polyester-forming catalyst metal such as lithium and an acid component such as terephthalic acid and an ester residue such as a polyester-forming intermediate oligomer. It can be selected from organic salts and the like. A single inert particle may be used, or two or more types of inert particles may be used in combination.

The shape of the inert particles is not particularly limited, but spherical, massive, and amorphous particles formed by aggregating primary particles are preferred from the viewpoint of hardness, adhesion to a polyester resin, and the like. The particle size distribution of the inert particles is preferably uniform and monodispersed in order to prevent the presence of coarse particles. When the average particle size of the inert particles to be used is in the range of 0.5 to 2.5 μm, it is most effective and preferable for the expression of slipperiness.
The amount of inert particles to be added is determined by the average particle size. Large particles with a large average particle size are added in small amounts, and small particles in an average particle size are added in large amounts. For example, when silica particles having an average particle size of 2.0 μm are used, the addition amount is preferably about 1000 ppm.

In the present invention, as a method for incorporating inert particles into the polyester, for example, a slurry of the inert particles is added at any stage before the polyester polycondensation reaction is substantially completed in the polyester production process. Then, a method of completing the polycondensation reaction, a method of kneading and extruding a polyester resin and inert particles or a slurry of inert particles, and the like are not limited thereto.

In order to achieve the object of the present invention, the inert particles used in the present invention are used in the step of preparing particles or a slurry thereof.
It is preferred that there are no coarse particles exceeding μm. When coarse particles having a size of 20 μm or more are present in the film, pinholes and cracks tend to be generated from the coarse particles. In order to remove such coarse particles, if necessary, wet / dry pulverization, classification by a method known per se,
The particle size can be adjusted by performing a treatment such as filtration.

The metal plate on which the film of the present invention is laminated is preferably made of aluminum, steel or an alloy containing these as a main component.
Electroformed steel, stainless steel, tinplate, tin-free steel, pure aluminum, aluminum alloy, tin-plated steel, nickel-plated steel, chrome-plated steel, galvanized steel, electrolytic galvanized steel, galvanized-aluminum alloy-plated steel, aluminum-plated steel Can be mentioned as a representative. These metal plates may be subjected to a surface treatment such as a phosphate treatment, a chromic acid treatment, a tin plating, a zinc plating, and a nickel plating as necessary.

As an example of a method of manufacturing a laminated metal plate by laminating the polyester film of the present invention on at least one side of a metal plate, there is a method by thermal lamination. For example, (1) a metal plate is heated in a heating furnace or an induction heating roll. A method in which the film is heated to a temperature equal to or higher than the melting point of the polyester film by a heating medium heating roll or the like and introduced into a laminating roll to thermally fuse the film; (3) heating the polyester film at a temperature higher than the melting point and lower than the melting point of the polyester film. The metal plate and polyester film are introduced into the laminated After thermal bonding the arm, although the polyester film by heating the laminated metal sheet again at a temperature higher than the melting point of the polyester film is introduced into a heating furnace and a method of immediately quenched after reaching a temperature above the melting point,
The methods (2) and (3) are particularly preferred. In the method (1), the surface of the polyester film which is not in contact with the metal plate is not preferable because the orientation remains without being destroyed.
Further, in order to prevent recrystallization of the film after lamination, a method of immediately cooling with a cooling roll, a cooling tank or the like is preferable.
As an example of a method of manufacturing another laminated metal plate, a laminating film is polyurethane-based, phenol-based,
Furan-based, urea-based, melamine-based, polyester-based, epoxy-based, silicone-based thermosetting resins, vinyl acetate,
Ethylene-vinyl acetate copolymer and its hydrolyzate,
Ethylene-acrylic acid copolymer, acrylic resin, thermoplastic resin such as polyamide, butadiene-acrylonitrile rubber, neoprene, other rubber derivatives, etc.
Lacquer, glue, casein, a method of laminating a metal plate via an adhesive layer made of an adhesive or the like such as a natural resin, and the like, but the laminating method is not limited thereto, and adopts another known method. be able to.

The metal can laminated with the polyester film of the present invention is made of the above-mentioned laminated metal plate, and is, for example, a three-piece can having a lid, a body and a bottom separately, a two-piece can having a can body integrated with the bottom and a lid, and the like. Molded.
The method of making cans from a metal plate is not particularly limited,
For example, as a manufacturing method of a two-piece can, there are a shallow drawn can by a drawing method, and a redrawn (DR
D) Cans, reduced-diameter drawn cans made by a draw-bending-stretching method, drawn ironed cans (DI cans) made by a drawn-ironing method (DI method), and the like. At least one surface of the metal plate refers to the inner surface of the can or the inner and outer surfaces after the can is made. The purpose of the present invention is to oxidize the contents, to prevent decay, and to maintain the flavor of the contents for a long period of time, at least on the inner surface side of the can after can production, at least a part or all over the film is laminated. Need to be

[0032]

The present invention will be described below in detail with reference to examples.

Example 1 As a copolymerized polyester resin, a polyester composed of 90 mol% of terephthalic acid, 10 mol% of isophthalic acid, and ethylene glycol as a diol component was produced by a direct weight method. At that time, 1000 ppm of amorphous silica particles having an average particle size of 2.0 μm and a particle size distribution substantially less than 20 μm were added to the polyester to complete the polymerization reaction. The obtained copolymerized polyester had a Tg of 75 ° C. and an IV of 0.65. The production of oxygen-absorbing polyester is performed by blending 5% by weight of polybutadiene diol having a molecular weight of 1200, 95% by weight of a copolymerized polyester, and 100 ppm of cobalt octenoate as cobalt.
Transesterification was performed by kneading and extruding at 270 ° C. for 4 minutes in a nitrogen stream using a reactive extruder to obtain an oxygen-absorbing polyester. The Tg of the oxygen-absorbing polyester was 60 ° C., and the heat resistance was good.

The above polyester resin is supplied to an extruder,
It was melt-extruded at 270 ° C., discharged from a die in a sheet form, and cast on a cooling drum. The unstretched sheet was longitudinally stretched by a roll stretching machine at a stretching temperature of 103 ° C. and a magnification of 3.3. The obtained film was introduced into a tenter, and was horizontally stretched at a stretching temperature of 120 ° C. and a magnification of 4.0. Subsequently, the stretched film was subjected to a 5% relaxation treatment at 230 ° C. in the transverse direction while being heat-fixed to obtain a biaxially stretched film having a thickness of 20 μm.

The obtained film was temporarily bonded to both sides of an aluminum plate having a thickness of 0.3 mm and a width of 20 cm, which was previously heated to 240 ° C. or higher, through a laminator, heated again at 260 ° C. to melt the film, and then rapidly cooled. To produce a laminated aluminum plate. The laminated aluminum plate thus obtained was cut into a circle having a diameter of 150 mm and drawn and ironed to prepare a DI can having a diameter of 66 mm, a height of 125 mm and a wall thickness of 0.12 mm.

While the resulting laminated aluminum can was filled with air, the can lid was tightly closed and sealed, and the amount of oxygen absorbed after standing at 22 ° C. for 70 days was measured. The oxygen concentration in the air in the can was reduced from 21% to 14%, and oxygen absorption was confirmed. In addition, beer was filled in the obtained laminated aluminum can, and the can lid was tightly closed and sealed. This was left at room temperature, the cans were separately opened every 10 days until 120 days, and on the 300th day, the odor was smelled, and the number of days until the off-odor was generated was examined. 12
Unpleasant odors were not observed in the beer in each can on day 0 and on day 300.

Example 2 An oxygen-absorbing polyester film, a laminated aluminum plate, and a laminated aluminum can were produced in the same manner as in Example 1 except that polybutadiene diol having a molecular weight of 2800 was used. A filling test was performed. In the oxygen absorption measurement, the oxygen concentration in the air in the can was reduced from 21% to 5%, and sufficient oxygen absorption was confirmed. Beer filling test until day 120 and 300
No off-flavor was confirmed in the beer in each can on the day.

COMPARATIVE EXAMPLE 1 Instead of using the oxygen-absorbing polyester, an example in which the acid component used in Example 1 was 90 mol% of terephthalic acid, 10 mol% of isophthalic acid, and only a copolymer polyester composed of ethylene glycol as the diol component was used. A film was produced in the same manner as in Example 1, then a laminated aluminum plate and a laminated aluminum can were produced, and the oxygen absorption measurement and beer filling test were conducted in the same manner. In the oxygen absorption measurement, the oxygen concentration in the air in the can was maintained at 21%, and almost no oxygen absorption was confirmed. In the beer filling test, an unusual smell was confirmed in the beer in the can on the 120th day.

[0039]

The metal plate laminated with the oxygen-absorbing polyester film of the present invention and a can made using the same can effectively absorb oxygen and have a low odor due to the generated volatile substances. When a content such as a beverage is filled, oxidation and decay of the content can be prevented, and the flavor of the content can be maintained for a long time.

Continued on the front page F term (reference) 4F100 AA01A AA01H AA19A AA19H AA20A AA20H AB01A AB01B AB01H AB02A AB02H AB03B AB10B AB14A AB14H AB15A AB15H AB16A AB16H AB17A AB17H AB31B AC04A AC04H AH02AH02AH02AH04A BA03 BA05 BA06 BA07 BA10A BA10B BA10C BA13 CA06A CA09A CA23A CA30A DA01 DE01A DE01H DJ00A DJ00H GB16 GB23 JD14 JL00 JL08A JL08H

Claims (13)

[Claims] 1. A metal plate comprising a polyester containing an aromatic dicarboxylic acid component and a glycol component as main components, and a film containing a high-molecular oxygen absorbent in the polyester is laminated on at least one surface of a metal plate. Film laminated metal plate. 2. The film-laminated metal plate according to claim 1, wherein the high molecular oxygen absorbent contained in the laminated film is a high molecular compound having a double bond in a molecule. 3. The film-laminated metal sheet according to claim 1, wherein the high molecular oxygen absorbent contained in the laminated film is polybutadiene diol. 4. The film-laminated metal plate according to claim 1, wherein the laminated film contains a transition metal as an oxygen absorption catalyst. 5. The method according to claim 1, wherein the transition metal is Co, Fe, Ni, M
The film-laminated metal sheet according to claim 4, wherein the metal sheet is at least one selected from n and Cu. 6. The film-laminated metal plate according to claim 1, wherein the laminated film contains an ultraviolet sensitizer. 7. The film-laminated metal plate according to claim 6, wherein the ultraviolet sensitizer is at least one selected from benzophenone and a derivative thereof. 8. The film-laminated metal plate according to claim 1, wherein the laminated film contains porous inorganic particles. 9. The film-laminated metal plate according to claim 8, wherein the porous inorganic particles are at least one selected from silica, alumina and zeolite. 10. The film-laminated metal plate according to claim 1, wherein an antioxidant is contained in the laminated film. 11. The film-laminated metal plate according to claim 1, wherein another resin having no oxygen absorbing property is laminated on the laminated film. 12. The film-laminated metal plate according to claim 1, wherein the metal plate is made of a material selected from the group consisting of aluminum, steel, and an alloy mainly containing them. 13. A film-laminated metal can made by using the film-laminated metal plate according to claim 1.