JPH0239335B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD OF THE INVENTION The present invention relates to a method for manufacturing deep-drawn containers, and more particularly to a method for manufacturing deep-drawn containers from steel foil or iron foil. Furthermore, the present invention also relates to a method for producing deep-drawn containers that have excellent corrosion resistance and commercial value. Prior Art and Technical Problems of the Invention Packaging materials used for containers and lids include various materials such as various metals, plastics, paper, glass, and ceramics, or composite materials of two or more of these materials. In terms of the combination of barrier properties against gases such as , carbon dioxide, and water vapor, and mechanical strength, metal materials are most suitable. However, since metal cans and metal lids are difficult to dispose of by incineration, etc., there is a problem of so-called can pollution, so we use packaging materials that are easier to dispose of.
Laminated bodies consisting of metal foil and resin film have come to be widely used in the field of sealed containers and sealed lids. Almost all commercially available laminates for containers or lids are based on aluminum foil, but even though aluminum foil has excellent appearance characteristics and flexibility, its surface is Even when coated with organic resin, contents containing relatively high concentrations of salts such as common salt and contents containing organic acids can cause problems such as corrosion such as pitting and peeling of the coating layer. , resulting in defects such as leakage of contents and decreased shelf life. As metal foils, those based on iron or steel such as iron foil, steel foil, and tin foil are also known, but when these are used as food packaging materials,
There are still many problems that need to be resolved.
That is, iron and steel are metals that are extremely susceptible to rust, and rust can occur during the manufacturing process or storage of a package, which can significantly reduce its appearance and commercial value. Further, iron elution and rust contamination significantly reduce the flavor retention of the contents. Furthermore, since iron or steel foils are significantly thinner than steel plates, they have poor drawing workability and formability, and there are problems such as wrinkles occurring during drawing processing and the foil being cut, making it impossible to form containers. This drawback becomes more noticeable when a relatively thick organic resin coating is applied to the iron or steel foil for the purpose of improving its corrosion resistance and rust resistance. Summary and Objectives of the Invention The present inventors provided a thermoplastic resin film coating on both sides of a steel foil or iron foil, and formed a laminate by drawing and forming a laminate in which at least the film on the inner surface of the container was filled with an inorganic filler. When attaching to
It has been found that deep drawability is significantly improved compared to a laminate not filled with an inorganic filler. That is, an object of the present invention is to provide a method for manufacturing deep-drawn containers from steel foil or iron foil. Another object of the present invention is to provide a method that can effectively prevent the occurrence of wrinkles, cutting of the foil, etc. during deep drawing of steel foil or iron foil into containers. Still another object of the present invention is to provide a deep-drawn container made of steel foil or iron foil, which is effectively prevented from rusting, iron elution, etc., and has improved commercial value. Structure of the Invention According to the present invention, both sides of a steel foil or iron foil are coated with a thermoplastic resin film, and at least the film layer on the inner surface of the container is filled with an inorganic filler in an amount of 2 to 50% by weight based on the thermoplastic resin. Provided is a method for manufacturing a deep-drawn container, which comprises subjecting a laminated material prepared in the above-mentioned form to deep-drawing. The steel foil or iron foil used in the present invention may be provided with a surface treatment layer on its surface. As will be described in detail later, this surface treatment layer may be any surface treatment layer known per se formed by plating, electrolytic treatment, chemical conversion treatment, chemical treatment, or the like. The thermoplastic resin film used for coating is
As will be detailed later, any material can be used as long as it is capable of forming a film and is water resistant. As the inorganic filler, any inorganic pigment or inorganic extender pigment can be used. Preferred embodiments of the invention The invention will be described in detail below with reference to the accompanying drawings. Laminated materials and effects As described above, the present invention, when drawing steel foil or iron foil, laminates thermoplastic resin films on both sides of the steel foil or iron foil, and in the film layer that becomes the inner surface of the container. It is characterized in that it is used in the form of a laminated material filled with an inorganic filler.
That is, the above-mentioned inorganic filler-filled film layer,
By providing it on the inner surface of the container, drawing formability is significantly improved, problems such as wrinkles and edge breakage are eliminated, and as shown in the example below, the critical drawing ratio can be significantly improved. can. The drawing ratio R is expressed by the formula R=D/d, where D is the diameter of the material subjected to drawing and d is the diameter of the punch used (the diameter of the bottom of the container). As the process progresses, drawing becomes impossible due to breakage. The maximum value of R that can be formed is called the limit drawing ratio,
A larger value means that deeper drawing is possible. Iron or steel foils are significantly inferior in drawability and formability to steel sheets due to thickness effects. This is because wrinkles occur during the drawing process, and even if the wrinkle suppressing force is increased to prevent wrinkles from occurring, the wrinkle suppressing force is not sufficiently transmitted to the foil surface through the organic coating. Furthermore, if the wrinkle pressing force is increased too much, iron or steel foil has low strength and will break, making it impossible to form a container. Since the inorganic filler in the organic resin coating makes the organic resin coating itself hard, it is thought that the wrinkle-pressing force is efficiently transmitted to the foil, making it possible to form a wrinkle-free squeezed container. Furthermore, by using the coating with the above-mentioned inorganic filler, the corrosion tendency of the corrosive components iron or steel foil is significantly suppressed, for example hydrogen generation is significantly suppressed, and the shelf life of the container is considerably extended. Even if rust occurs on the iron or steel foil during long-term storage, this rust is concealed and good appearance characteristics are maintained over a long period of time, thereby increasing the commercial value. In FIG. 1 showing an example of the laminated material used in the present invention, surface treatment layers 2a and 2b are provided on both sides of a base 1 made of steel foil or iron foil, and the side that becomes the inner surface of the container (the lower side in the figure) is provided with surface treatment layers 2a and 2b. ) is provided with an inorganic filler-filled thermoplastic resin film inner surface layer 4 via an adhesive layer 3a if necessary. Further, on the side that becomes the outer surface of the container, a thermoplastic film outer surface layer 5 is provided via an adhesive layer 3b if necessary. Of course, the outer layer 5 may be a resin film layer not filled with an inorganic filler, but it is generally preferable to be a film layer filled with an inorganic filler like the inner layer 4. In the present invention, iron or steel foil is used because
This is because compared to aluminum foil, the pitting rate for contents containing salt is significantly lower, and this can significantly improve the corrosion resistance and gas barrier properties of packaging materials. .
Furthermore, iron or steel foil has a Young's modulus approximately 2.5 times that of aluminum foil, and can provide sufficient strength and shape retention with a relatively thin thickness. Furthermore, iron or steel foil is available relatively cheaply compared to aluminum foil, and can also reduce the cost of the container. It is also important that this iron or steel foil has a thickness of 10 to 120 μm, in particular 30 to 100 μm. If the thickness is less than the above range, it is difficult to obtain a foil without defects such as pinholes, and various gases,
It is difficult to obtain sufficient barrier properties against water vapor and the like. Moreover, if the above range is exceeded, disposal of the final container may become difficult or the economy or other advantages of using the foil may be lost. As the foil substrate, iron foil is used when flexibility or pliability is required, and steel foil is used when rigidity and mechanical strength necessary for shape retention are required. Iron foil is obtained by electrodepositing an electrolyte containing ferrous chloride, ferrous sulfate, etc. onto the surface of a metal substrate as a cathode, and then peeling the formed film from the surface of the substrate. It has extremely high purity (over 99.97% Fe), excellent corrosion resistance, and is softer than steel foil. Further, steel foil has a structure in which crystal grains are elongated in the rolling direction, whereas iron foil has a columnar crystal structure in which crystals grow in the thickness direction. Both ductile and full hard steel foils are used. For the former type, cold rolled steel sheets are annealed, then subjected to secondary cold rolling, annealed again, and, if necessary, subjected to one of the following post-treatments: galvanizing, tin plating, nickel plating, electrolytic chromic acid treatment, or chromic acid treatment. Alternatively, it can be obtained by performing two or more of them. The latter type is obtained by subjecting a cold-rolled steel plate to secondary cold rolling after annealing and, if necessary, performing post-treatments such as galvanizing, tin plating, nickel plating, electrolytic chromic acid treatment, and chromic acid treatment. A fully hard-type steel plate with a metal plating layer is also manufactured by annealing a cold rolled steel plate, subjecting it to tempering treatment, applying metal plating thereto, and then subjecting it to secondary cold rolling. An example of the mechanical properties of soft steel foil, hard steel foil, and iron foil is as follows. Tensile strength and elongation are generally 30 to 50 Kg/mm ² and 15 to 35%, respectively, for soft steel foil, 40 to 60 Kg/mm ² and 1 to 15%, respectively, for hard steel foil, and 1 to 15%, respectively, for iron foil.
It is in the range of 30-50Kg/mm ² and 2-10%. Generally, it is desirable to use steel foil. In the present invention, it is desirable for the iron or steel foil 1 to have a metal plating layer or a surface treatment layer made of a chromate layer thereon from the viewpoints of corrosion resistance and adhesion of the organic resin coating. Although the organic resin coating is effective in preventing direct contact between the contents and iron or steel foil, the resin coating can prevent hydrogen ions from the highly corrosive organic acids contained in the contents. It has the property of being able to pass through it fairly easily, and anions such as chloride ions contained in salts also pass through it, albeit to a small extent. For this reason, the coating tends to peel off at the interface between the organic resin coating and the foil, and once such peeling occurs, corrosion such as rust, iron leaching, and pitting easily progresses in this area. Become. According to a preferred embodiment of the present invention, by providing a surface treatment layer consisting of a metal plating layer or further a chromate layer on the iron or steel foil, this metal plating layer acts as a barrier layer against the above-mentioned corrosive components, Furthermore, it acts to enhance the adhesion with the organic resin coating layer. At this time, when a chromate layer is provided on the metal plating layer, the adhesion with the organic resin coating is further improved. Typical examples of metal plating layers include metals that are softer than iron and have anti-corrosion effects against iron;
For example, metals such as Ni, Sn, Zn, Al, etc. are advantageously used. The plating layer made of these metals not only has an excellent anti-corrosion effect, but also has good drawing formability, and when cutting iron or steel foil, the plating layer metal flows to the cut edge, causing the cut edge to form. It shows an unexpected and novel effect of protecting the cut edge and suppressing the occurrence of rust from the cut edge. The fact that the plating metal flows and exists at the cut edge of iron or steel foil with a plating layer is confirmed by the presence of the plating layer metal when the cut edge is observed with an X-ray microanalyzer. Ru. In the metal plating layer, it is preferable that a metal having a hardness of Vickers hardness Hv500 or less, more preferably Hv400 or less exists in a coating amount of 0.1 to 15 g/m ² , particularly 0.2 to 12 g/m ² . That is, if the hardness of the metal exceeds the above range, the plating layer metal will not flow to the cut edge when cutting iron or steel foil, and the effect of preventing rust on the cut edge will not be obtained. Further, if the amount of metal plating is at the end of the above range, the effect of blocking corrosive components or preventing corrosion is unsatisfactory, and in particular, the effect of preventing rust from forming on cut edges cannot be obtained. Furthermore, it is economically disadvantageous to provide the plating layer beyond the above range, which cancels out the advantages of using iron or steel foil. A nickel plating layer has a particularly excellent shielding effect against corrosive components, and an example of an easily available plated iron or steel foil is tin plated foil, that is, tin foil. In this tin foil, sufficient corrosion resistance and organic film adhesion can be obtained even when the amount of tin coated is relatively small, for example in the range of 0.5 to 10 g/m ² , and in this case, the tin layer exists as a metallic tin layer. However, from the viewpoint of resin adhesion, it is preferable to exist in the form of a tin-iron alloy layer in which the Sn/Fe metal atomic ratio is within the range of 2 to 1. Examples of the chromate layer include a chromium oxide layer mainly composed of hydrated chromium oxide having a coating amount of Cr in the range of 1 to 50 mg/m ² , particularly 3 to 35 mg/m ² . This chromate layer can be formed on the plating layer described above by a known chemical conversion treatment and/or chemical treatment. In the present invention, in the case of a container in which rust formation at the cut edge is not a problem, for example, a draw-formed container with curled edges, the plating layer is a metal chromium layer, and a taint layer having a chromate layer on top of the plating layer is used. It may also be a free steel foil.
This metallic chromium layer has a thickness of 0.03 to 0.5 g/m ² , especially 0.05 g/m 2 .
It is preferably present in a coverage of 0.3 g/m ² to 0.3 g/m 2 . Further, the metal plating layer is not limited to being composed of a single metal layer, but can also be composed of a plurality of different types of metal layers. For example, the base plating layer is the above-mentioned soft metal layer such as nickel, and the top plating layer is a chromium metal layer formed by electrolytic chromic acid treatment, and further has a chromium oxide layer thereon. good. In the present invention, an organic resin coating is provided on both sides of the above-mentioned iron or steel foil, and in this case, at least the resin layer on the inner surface of the container, preferably the resin layers on both sides, are filled with an inorganic filler. Inorganic fillers include rutile-type or anatase-type titanium dioxide, zinc white, inorganic white pigments such as gloss white; barite, precipitated barite sulfate, calcium carbonate, gypsum, precipitated silica, aerosil, talc, calcined or uncalcined clay. , barium carbonate, alumina white, synthetic or natural mica, synthetic calcium silicate, magnesium carbonate, barium carbonate, and other white extender pigments; carbon black, magnetite, and other black pigments; red pigments, such as red iron; yellow pigments, such as sienna; Examples include blue pigments such as ultramarine blue and cobalt blue, but the inorganic fillers that can be used in the present invention are not limited to those exemplified above. These inorganic fillers have an average particle size of
The specific gravity is preferably in the range of 0.05 to 20 μm, and from the viewpoint of drawability, it is desirable that the specific gravity is in the range of 2.0 to 9.0. Furthermore, in terms of hiding power and barrier properties, it is desirable that the hiding power according to JIS K-5101 is 50 cm ² /g or more. Inorganic fillers particularly suitable for the purposes of the invention include titanium dioxide, especially rutile titanium dioxide. This titanium dioxide has the greatest anti-corrosion effect among various pigments against corrosion of steel foil etc. caused by corrosive components, and also has excellent hiding power, making it possible to maintain the white color of packaging containers permanently. becomes. Suitable examples of organic thermoplastic resins include, but are not limited to: (a) Polyolefins; polypropylene, polyethylene, polybutene-1, propylene-ethylene copolymer, propylene-butene-1 copolymer, ethylene-vinyl acetate copolymer, ionically crosslinked olefin copolymer (ionomer). (b) Polyamides; especially general formulas or Polyamides consisting of repeating units represented by the formula, where n is a number from 3 to 13 and m is a number from 4 to 11. For example, poly-ω-aminocaproic acid, poly-ω-aminoheptanoic acid, poly-ω-aminocaprylic acid, poly-ω-aminopelagoic acid, poly-ω-aminodecanoic acid, poly-ω-aminoundecanoic acid, poly-ω -Aminododecanoic acid, poly-ω-aminotridecanoic acid, polyhexamethylene adipamide, polyhexamethylene sebamide, polyhexamethylene dodecamide, polyhexamethylene tridecamide, polydecamethylene adipamide, polydeca Methylene sebamide, polydecamethylene dodecamide, polydecamethylene tridecamide, polydodecamethylene adipamide,
Polydodecamethylene sebamide, polydodecamethylene dodecamide, polydodecamethylene tridecamide, polytridecamethylene adipamide, polytridecamethylene sebacamide, polytridecamethylene dodecamide, polytridecamethylene tridecamide , polyhexamethylene azelamide,
Polydecamethylene azeramide, polydodecamethylene azeramide, polytridecamethylene azeramide, or a copolyamide thereof. (c) Polyesters; especially general formulas Or In the formula, R ₁ is an alkylene group having 2 to 6 carbon atoms,
R ₂ is an alkylene group or arylene group having 2 to 24 carbon atoms, and a polyester consisting of a repeating unit represented by the following. For example, polyethylene terephthalate, polyethylene terephthalate/isophthalate, polytetramethylene terephthalate, polyethylene/tetramethylene terephthalate, polytetramethylene terephthalate/isophthalate,
Polyethylene terephthalate/isophthalate, polytetramethylene/ethylene terephthalate, polyethylene/tetramethylene terephthalate, isophthalate, polyethylene/oxybenzoate, or blends thereof. (d) Polycarbonates; especially general formula A polycarbonate represented by the following formula, where R ₃ is a hydrocarbon group having 8 to 15 carbon atoms. For example, poly-p-xylene glycol biscarbonate, poly-dioxydiphenyl-methane carbonate, poly-dioxydiphenyl ethane carbonate, poly-dioxydiphenyl 2,2-propane carbonate, poly-dioxydiphenyl 1 , 1-ethane carbonate. (e) Vinyl chloride resins such as polyvinyl chloride, vinyl chloride-butadiene copolymer, and vinyl chloride-styrene-butadiene copolymer. (f) vinylidene chloride-vinylidene chloride copolymer,
Vinylidene chloride resin such as vinylidene chloride-vinylpyridine copolymer. (g) High nitrile resins such as high nitrile content acrylonitrile-butadiene copolymers, acrylonitrile-styrene copolymers, acrylonitrile-styrene-butadiene copolymers. (h) Polystyrene resin, styrene-butadiene copolymer, styrene-acrylonitrile copolymer, ABS resin, etc. These resins are generally formed into a film shape and adhered to the above-mentioned steel foil by thermal fusion or bonded using an adhesive. Adhesives that are excellent for a wide range of thermoplastic resin films and steel foils are urethane adhesives, and for polyolefin films, acids graft-modified with ethylenically unsaturated carboxylic acids or their anhydrides are suitable for use with polyolefin films. Modified olefin resins can be used, and low-melting copolyamides can be used as adhesives for polyamide films, and low-melting copolyesters can be used for polyester films. Further, as an adhesive undercoat, an epoxy-phenol paint containing an adhesion promoter such as an acid-modified olefin resin may be applied, and the film layer may be thermally bonded through this undercoat layer. The thickness of the thermoplastic resin film layer is generally 10 to
The thickness is preferably 150 μm, particularly within the range of 30 to 100 μm; if it is thinner than this range, the coating effect against corrosion by the resin film tends to be lost, and if it is thicker than this range, drawability is reduced. The amount of inorganic filler filled in the resin varies depending on the thickness of the film, etc., but it is preferably in the range of 2 to 50% by weight, particularly 5 to 30% by weight, based on the resin. If the filling amount is lower than the above range, the effect of improving the rigidity of the film layer and suppressing the occurrence of wrinkles will be unsatisfactory, and the corrosion resistance and hiding effect will also likely be unsatisfactory. On the other hand, if the amount exceeds the above range, the properties of the film become brittle, and pinholes, cracks, tears, and peeling are likely to occur in the film during drawing. Drawing Forming Deep drawing forming according to the present invention can be easily performed by using the above-described laminated material as a raw material. That is, the second
In the figure, a material 10 obtained by shearing the above-described laminated material into a predetermined size and shape is held by a wrinkle presser 11.
While being held down with
Form into a seamless cup with a bottom. In this case, according to the method of the present invention, since the inorganic filler-filled film layer is located at least on the side of the wrinkle presser 11, the generation of wrinkles is effectively suppressed, and the formula R=D A remarkable feature is that the aperture ratio defined by
It can be increased to a certain extent. Generally, a single drawing operation is sufficient, but if desired, two or more stages of drawing operations may be performed. In drawing forming, an ordinary metal punch can be used as the punch 12. However, as shown in FIG.
(Patent No. 1130414) can further suppress the occurrence of wrinkles. A fourth example of a deep-drawn container according to the present invention
In the figure, this container 20 has a bottom part 21 and a side wall part 2 that is perpendicular to the bottom part or widens upward.
2 and a flange portion 23 provided at the upper end of the side wall portion.
It consists of. There is a cut edge 24 on the outside of this flange portion 23, and as mentioned above, the occurrence of rust is suppressed by covering the steel foil or iron foil with a plating metal layer. In addition, iron or steel foils have sharp cutting edges that can easily cause damage to fingers, etc., but according to the present invention, by providing a resin coating layer with the thickness described above, the above-mentioned dangers can be avoided. It has now become possible to ensure the safety of packaging materials using iron or steel foil. In FIG. 5 showing another example of a deep-drawn container according to the present invention, this container is formed from a bottom portion 21, a side wall portion 22 and a flange portion 23, similar to the container in FIG. A curled portion 25 formed by rolling the laminated material is provided at the outermost edge of the portion 23. It should be understood that the bottom shape of these containers can be any shape, such as circular, oval, square, rectangular, hexagonal, octagonal, etc. Furthermore, it should be understood that by using a heat-sealable resin film as the inner surface material resin, it is possible to easily seal with the lid material by heat sealing. The invention is illustrated by the following example. Example 1 Both sides of a 75μ thick steel foil were subjected to cathodic electrolysis in an electrolytic chromic acid treatment bath (an aqueous solution of chromic anhydride 60g/, sulfuric acid 0.2g/, and sodium silicofluoride 0.2g/),
After providing a surface treatment layer of metallic chromium with a thickness of 0.1g/ ^m2 and a chromate layer with a thickness of 15mg/ ^m2 , 5wt% of rutile titanium dioxide is applied to the inner surface of the container using a urethane adhesive. A filled polypropylene film with a thickness of 70μ was laminated on the outer surface, and a polypropylene film with a thickness of 30μ without filler was laminated on the outer surface side. The material obtained in this way was evaluated for the critical drawing ratio and the appearance of the container using the method shown in FIG. Further, for evaluation of the corrosion resistance of the container, a cylindrical deep-drawn cup with a flange having a bottom diameter of 66 mm and a height of 32 mm was molded as shown in FIG. On the other hand, apply a Watts bath (nickel sulfate 240g/
, aqueous solution of nickel chloride 45g/, boric acid 30g/) and plated nickel to a thickness of 2.0g/ ^m2 ,
Next, cathode electrolysis was carried out in the electrolytic chromic acid treatment bath described above, and after a surface treatment of metallic chromium with a thickness of 0.05 g/m ² and chromate layer with a thickness of 15 mg/m ² was applied, one side was coated with epoxy/phenol paint. A 50μ thick polypropylene film was laminated on the other side using urethane adhesive. The thus obtained material was punched out into a circular shape with a diameter of 70 mm to create a heat-sealed lid. Next, the deep-drawn cup was filled with tuna dressing, the lid was heat-sealed, and then heat sterilized at 116°C for 40 minutes. After storage at 37°C for 6 months, the internal and external conditions of the deep-drawn cup container and lid were observed, and the amount of hydrogen generated in the head space was measured. Display the results -
Shown in 1. Examples 2 and 3 Same as Example 1 except that the content of titanium dioxide in the inner film was 10 wt% and 30 wt%, and the outer film also contained 10 wt% titanium dioxide. Tested and evaluated. The results are shown in Table-1. Comparative example 1 No filler on inner and outer surfaces, thickness 70μ
Table 1 shows the results of the tests and evaluations conducted in the same manner as in Example 1 except that a 30μ polypropylene film was used. Comparative Examples 2 and 3 The inner film contains 60wt% titanium dioxide at a thickness of 70μ, and titanium dioxide at a thickness of 160μ, respectively.
It is a polypropylene film containing 10wt%, and the outer film is 30μ thick and made of titanium dioxide.
Table 1 shows the results of tests and evaluations conducted in the same manner as in Example 1, except that a polypropylene film containing 10 wt% was used. Examples 4, 5, and 6 A polypropylene film having a thickness of 40μ and containing 10wt% titanium dioxide was used as the inner surface film, respectively.
A polypropylene film with a thickness of 70μ and containing 10wt% titanium dioxide, a medium-density polyethylene film with a thickness of 70μ and containing 20wt% titanium dioxide, and -4 with a thickness of 40μ and titanium dioxide.
Table 1 shows the results of the tests and evaluations conducted in the same manner as in Example 1, except that the 10 wt% polypropylene film and -5 and 6 were unstretched nylon films with a thickness of 40 μm. Example 7 Table 1 shows the test and evaluation results in the same manner as in Example 1, except that polypropylene films with thicknesses of 70 μm and 40 μm filled with 30 wt % zinc white were used as the inner and outer films. Example 8 Table 1 shows the results of tests and evaluations carried out in the same manner as in Example 1, except that polypropylene films with thicknesses of 70 μm and 40 μm filled with 30 wt % barite were used as the inner and outer films.

【table】

【table】 [Brief explanation of drawings]

Fig. 1 is a sectional view of the laminated material used in the present invention, Fig. 2 is a sectional view illustrating the deep drawing method, Fig. 3 is a sectional view of a forming punch, and Fig. 4 is a sectional view of the forming punch according to the present invention. FIG. 5 is a diagram showing an example of a deep-drawn container.
FIG. 1 is a diagram showing an example of a deep-drawn container according to the present invention. 1 is a base of steel foil or iron foil, 2a and 2b are surface treatment layers, 3a and 3b are adhesive layers, 4 is an inorganic filler-filled thermoplastic resin film, 5 is an outer thermoplastic resin film, 10 is a laminate material, 11 12 is a punch, 13 is a die, 14 is a metal core of the punch, 15 is a rubber, 20 is the entire container, 21 is a bottom of the container, 22 is a side wall, 23 is a flange, 2
4 indicates a cut edge, and 25 indicates a curl portion.

Claims (1)

[Claims] 1. Both sides of the steel foil or iron foil are covered with a thermoplastic resin film, and at least the film layer on the inner surface of the container contains an inorganic filler in an amount of 2 to 20% per thermoplastic resin.
A method for producing a deep-drawn container characterized by subjecting a laminated material filled in an amount of 50% by weight to deep drawing. 2. The method according to claim 1, wherein the steel foil or iron foil is provided with a surface treatment layer consisting of a metal plating layer and/or a chromate layer.