Molded containers and packaging body for storing fat-containing foods

Abstract

To provide a molded container that is unlikely to get discolored and smell even when processed foods containing a large amount of fat such as curry and stew are stored for a long period of time.SOLUTION: The molded container for storing fat-containing foods that is made of a metal laminate packaging material, is formed by molding a metal laminate packaging material 10, in which a thermosetting resin layer 10a made of homopolypropylene film, a barrier layer 10c made of a metal foil and a protective resin layer 10d made of a synthetic resin film are sequentially laminated, so that the thermosetting resin layer 10a is configured to be an inner surface.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a molded container suitable for storing oil-containing foods, and a package using the molded container. In this specification, aluminum includes pure aluminum and aluminum alloys, unless otherwise specified. [Background technology]

[0002] Cans and bottles have long been used to store processed foods for long periods. However, bottles are heavy and break easily, and cans can be cut after opening, making them difficult to transport and handle. For this reason, molded containers made of lightweight and flexible laminated packaging materials are widely used.

[0003] Known examples of laminate packaging materials include metal laminate packaging materials (so-called high barrier films) in which both sides of a metal foil are laminated with a synthetic resin film. Among metal laminate packaging materials, aluminum laminate packaging materials in which a synthetic resin film is attached to both sides of an aluminum foil have a high blocking effect against light, moisture, oxygen, etc. Therefore, aluminum laminate packaging materials are highly used as materials for various molded containers (so-called high barrier molded containers), particularly for food applications.

[0004] As an example of a high-barrier molded container, Patent Document 1 discloses a container made by dry laminating an aluminum laminate packaging material made of a polyethylene terephthalate film, an aluminum foil, a modified polypropylene film, and a polypropylene film, with the polypropylene film as the innermost surface.

[0005] High-barrier molded containers have traditionally been used to store solid or semi-solid foods that contain a lot of moisture, such as jellies, puddings, and baby foods. On the other hand, foods that contain a lot of fats and oils, such as curry, stew, and pasta sauce (hereinafter also referred to as fat-containing foods), are generally packaged and distributed in pouch-shaped containers as so-called retort foods.

[0006] Meanwhile, the demand for retort foods has been increasing in recent years. Behind this lies a major change in the lifestyles of consumers, such as an increase in dual-income households and single-person households, and the emergence of stay-at-home demand. However, retort foods in pouch-shaped containers usually need to be transferred to tableware such as plates or bowls after cooking, which requires the effort of washing the dishes, and so they tend to be disliked, especially by single-person households. In addition, natural disasters such as earthquakes, typhoons, and floods have occurred frequently around the world in recent years, and tableware is not always available in disaster areas or evacuation areas. In this regard, high-barrier molded containers can be used not only as cooking utensils but also as tableware as they are, so the demand for them has been steadily increasing in recent years as a convenient means of providing retort foods. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent No. 2866916 Summary of the Invention [Problem to be solved by the invention]

[0008] However, when oil-containing foods such as curry and stew are stored in a high-barrier molded container for a long period of time, coloring and odor components dissolved in the oil may permeate the innermost layer of the molded container, causing strong coloring and aroma. In particular, in cup-shaped molded containers and tray-shaped molded containers, the outermost layer of the bent portion is greatly stretched while the innermost layer is strongly shrunk, and strong coloring may occur in such shrunk portions. [Means for solving the problem]

[0009] The present invention aims to provide a high-barrier molded container using a metal laminate packaging material, which is less likely to suffer from the problems of coloration and flavoring, especially in processed areas, even when storing oil-containing foods for long periods of time.

[0010] The inventors came up with the idea that by forming the innermost surface of a molded container from a synthetic resin film having a homogeneous and dense crystal structure, it would be difficult for coloring components and odor components contained in the oil-containing food, which is the content, to migrate to the inside of this innermost surface. They then found that by selecting a homopolypropylene film as the synthetic resin film, it is possible to obtain a molded container and a package that can solve the above-mentioned problems. That is, the present invention relates to the following molded container and package.

[0011] 1) A molded container made of a metal laminate packaging material for storing oil-containing foods, the container having an opening and a flange portion formed in an annular shape around the periphery of the opening, the metal laminate packaging material having a heat-sealable resin layer made of a homopolypropylene film, a barrier layer made of a metal foil, and a protective resin layer made of a synthetic resin film, the heat-sealable resin layer forming the innermost surface of the container, and the protective resin layer forming the outermost surface of the container. The homopolypropylene film is a film made of polypropylene obtained by copolymerizing propylene with an α-olefin. A molded container comprising:

[0012] 2) The thickness of the homopolypropylene film constituting the heat-sealable resin layer is 20 to 400 μm. 1) A molded container.

[0013] 3) The α-olefin is ethylene and / or 1-butene. , 1) or 2) molded container.

[0014] 4) The molded container according to any one of 1) to 3), wherein the content of the α-olefin in the homopolypropylene film is less than 10 mol %.

[0015] 5) The molded container according to any one of 1) to 4), wherein the homopolypropylene film is of a non-oriented type.

[0016] 6) A reinforcing layer made of a polyolefin film is interposed between the heat-sealable resin layer and the barrier layer. 5) Any of the above molded containers.

[0017] 7) The polyolefin film constituting the reinforcing layer is a laminate film of at least two layers, and includes at least a poly(propylene-ethylene) random copolymer layer and / or a polypropylene-polyethylene block copolymer layer. 6) Molded container.

[0018] 8) The polyolefin film constituting the reinforcing layer contains a filler. , 6) or 7) Molded container.

[0019] 9) The filler is titanium dioxide. , 8) Molded container.

[0020] 10) A base layer is formed on one or both sides of the barrier layer by chemical conversion treatment. , 1)~ 9) Any of the above molded containers.

[0021] 11) The metal foil constituting the barrier layer is an aluminum foil. , 1)~ 10) Any of the above molded containers.

[0022] 12) 1)~ 11) A heat-sealed package comprising any one of the molded containers described above, an oil-containing food, and a lid whose innermost surface is formed of a heat-sealable resin, wherein a heat-sealed portion is formed between the heat-sealable resin layer of the lid and a heat-sealable resin layer forming the upper surface of the flange portion of the molded container. Effect of the Invention

[0023] 1) ~11) Since the molded container is a container molded from a specified metal laminate packaging material, it has good water, gas, light, and other blocking properties. Therefore, it is suitable for long-term storage of various foods, particularly oil-containing foods such as curry, stew, and pasta sauce, which are rich in flavor. In addition, the heat-sealable resin layer that forms the innermost surface of this molded container is made of a homopolypropylene film having a uniform and dense crystal structure, and oils and fats derived from the oil-containing foods are unlikely to penetrate into this film. Therefore, even if the oil-containing foods are stored in this molded container for a long period of time, coloring and flavor derived from the oils and fats are unlikely to occur over the entire inner surface. This is particularly noticeable in the bent portions of this molded container. Thus, 1) ~11) The molded container has good resistance to coloration and odor.

[0024] 6)~9)The molded container of has a reinforcing layer made of a polyolefin film between the heat-sealable resin layer and the barrier layer, which is the innermost layer, and therefore has good resistance to coloring and odor and also has better mechanical properties. In addition, due to the presence of this reinforcing layer, delamination is not observed on one or both sides of the barrier layer.

[0025] 7) In the molded container, the polyolefin film forming the reinforcing layer is composed of a laminated film of two or more layers, and this laminated film is composed of a poly(propylene-ethylene) random copolymer layer and / or a polypropylene-polyethylene block copolymer layer, so that it has good coloring resistance and odor resistance as well as good mechanical properties. In addition, since it has improved heat resistance and water resistance, a package using this molded container does not suffer from defects such as delamination or peeling in the heat-sealed part even when heated in hot water, for example.

[0026] 10) The molded container has a base layer formed by chemical conversion treatment on one or both sides of the barrier layer, and therefore when a predetermined heat-sealable resin layer or reinforcement layer is bonded to the upper surface of the barrier layer by an adhesive, or when a predetermined protective resin layer is bonded to the lower surface of the barrier layer by an adhesive, it exhibits good interlayer adhesion, and therefore has good coloring resistance and odor resistance, as well as very good mechanical performance. In addition, since heat resistance and water resistance are also improved, a package using this molded container does not suffer from defects such as delamination or peeling at the heat-sealed part even when heated in hot water, for example. In addition, since the base layer itself functions as a barrier layer, a package containing an oil-containing food in this molded container is suitable for longer storage.

[0027] 11) The formed container is lightweight and low-cost because the metal foil forming the barrier layer is aluminum foil. In addition, since aluminum foil has good ductility, the formed container is free of cracks and pinholes in the aluminum foil even when produced by a forming method involving large deformation such as deep drawing or stretch forming.

[0028] 12) When the package of the present invention is taken out of an oil-containing food such as curry, stew, or pasta sauce after long-term storage, the innermost surface of the molded container constituting the main body is hardly discolored, particularly in the bent portion. In addition, there is no residual odor. Depending on the type of molded container of the main body, the package of the present invention is more excellent in some or all of the mechanical properties such as impact resistance and durability, heat resistance, water resistance, and ease of opening. [Brief description of the drawings]

[0029] [Figure 1] 1A and 1B are cross-sectional views of one embodiment of a metal laminate packaging material constituting a formed container of the present invention, in which (a) shows a basic configuration and (b) shows a modified example. [Diagram 2] FIG. 1 is a perspective view of one embodiment of a molded container of the present invention. [Diagram 3] 1A and 1B are partial cross-sectional views of one embodiment of the packaging body of the present invention, in which (a) shows an embodiment in which no opening notch is engraved on the upper surface of the flange portion, and (b) shows an embodiment in which a opening notch is engraved on the upper surface of the flange portion. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0030] Hereinafter, an embodiment of the present invention will be described with reference to Figures 1 to 3. However, these drawings are merely examples and do not limit the scope of the present invention.

[0031] Fig. 1 is a cross-sectional view of one embodiment of a metal laminate packaging material (10) constituting a molded container (1) of the present invention. In the metal laminate packaging material (10) of Fig. 1(a), a heat-sealable resin layer (10a), a barrier layer (10c), and a protective resin layer (10d) are laminated in this order. In the metal laminate packaging material (10) of Fig. 1(b), a heat-sealable resin layer (10a), a reinforcing layer (10b), a barrier layer (10c), and a protective resin layer (10d) are laminated in this order. However, the reinforcing layer (10b) is optional and can be omitted.

[0032] 2 is a perspective view of one embodiment of the formed container (1) of the present invention. The formed container (1) is made of a metal laminate packaging material (10) and is surrounded by an upper opening (11), a peripheral edge (12) of the opening (11), a flange portion (13) formed in an annular shape at the peripheral edge (12), a cylindrical side wall (14) extending downward and connected to the flange portion (13) at the boundary of the peripheral edge (12), and the side wall (14). bottom The flange portion (13) is made up of a wall (15) and an annular opening notch (16) is formed on the upper surface of the flange portion (13).

[0033] 3 is a cross-sectional view of one embodiment of the package (2) of the present invention. The package (2) is a heat-sealed sealed body including the molded container (1) of the present invention, the oil-containing food (3) as the content, and the lid (4) as the sealing means.

[0034] The heat-sealable resin layer (10a) is a layer that forms the innermost surface of the molded container (1) and is a layer that is heat-sealed to the lower surface of the lid (4), and is composed of a homopolypropylene film (A). The homopolypropylene film (A) is a film made of a homopolymer of propylene and has a relatively homogeneous and dense crystal structure, and therefore has excellent oil resistance. In addition, since the homopolypropylene film (A) has good hinge characteristics, voids are unlikely to occur inside even if it is deformed during the molding of the metal laminate packaging material (10). For the reasons exemplified above, even if an oil-containing food (3) is contained in the molded container (1), coloring components and odor components derived from the oil-containing food (3) are unlikely to penetrate into the heat-sealable resin layer (10a), and as a result, the molded container (1) exhibits good resistance to coloring and odor. As the homopolypropylene film (A), various known ones can be used, for example, a film made of isotactic homopolypropylene obtained by coordination anionic polymerization of propylene in the presence of a Ziegler catalyst such as titanium chloride (III)-diethyl aurumium chloride. Also included are films made of homopolypropylene obtained by the BASE method, the Anoco method, the UCC method, etc. The filming means is not particularly limited, and various known (co)extrusion molding methods (inflation, T-die, etc.), stretching methods, lamination methods, etc. can be adopted, and these methods may be combined. In addition, in the case of the stretching method, the homopolypropylene film (A) may be either a stretched type or a non-stretched type. If a non-stretched type is selected, the coloring resistance and odor resistance of the molded container (1) will be better. When the homopolypropylene film (A) has a more homogeneous and dense crystal structure, the coloring resistance and odor resistance of the molded container (1) are improved. From this viewpoint, the homopolypropylene film (A) preferably has a melting point of 160°C or more and a crystalline melting energy of 65 J / g or more. Here, the "melting point" refers to the melting peak temperature (Tmp) measured by differential scanning calorimetry (hereinafter, DSC) in accordance with JIS K7121-1987. The "crystalline melting energy" refers to the peak heat of fusion (crystalline melting energy, ΔH) measured by DSC in accordance with JIS K7122-1987. In addition, when there are multiple peak values ​​of Tmp and ΔH, the maximum values ​​are adopted. The melting point and crystalline melting energy are preferably 160 to 165°C and 65 to 80 J / g, respectively, and in this case, the coloring resistance and odor resistance of the molded container (1) are better. Furthermore, when the homopolypropylene film (A) has a tensile yield stress (hereinafter sometimes abbreviated as TYS) of 25 MPa or more, the molded container (1) has good coloring resistance and odor resistance, and also has excellent mechanical properties such as impact resistance and durability. Here, the "tensile yield stress" is a measurement value in accordance with JIS K7127, and is the arithmetic average value of the TYS in the MD direction and the TYS in the TD direction. The tensile yield stress is preferably 25 to 45 MPa, more preferably 31 to 39 MPa, and in this case, the mechanical properties of the molded container (1) are better. In this case, the TYS in the MD direction is usually 34 to 40 MPa, and the TYS in the TD direction is usually 28 to 38 MPa. As the homopolypropylene film (A), a film made of polypropylene obtained by copolymerizing propylene with a small amount of other α-olefins such as ethylene or 1-butene may be used as long as the coloring resistance and odor resistance of the molded container (1) are not significantly impaired. Examples of α-olefins include ethylene and / or 1-butene. The content of α-olefins in the homopolypropylene film (A) is less than 10 mol%. The thickness of the homopolypropylene film (A), i.e., the thickness of the heat-sealable resin layer (10a), is not particularly limited, but taking into consideration the formability of the metal laminate packaging material (10) and the color resistance, odor resistance, and heat resistance of the molded container (1), it is usually 20 to 400 μm, preferably 40 to 350 μm.

[0035] An adhesive layer (101) (not shown) may be provided between the heat-sealable resin layer (10a) and the reinforcing layer (10b) or the barrier layer (10c). Various known adhesives can be used for the adhesive layer (101), such as polyurethane resin adhesives, acrylic resin adhesives, epoxy resin adhesives, polyolefin resin adhesives, and elastomer adhesives, and two or more of these adhesives can be used in combination. Among these, polyurethane resin adhesives are preferred, and two-component curing polyether-urethane resin adhesives and / or two-component curing polyester-urethane resin adhesives are particularly preferred. The adhesive layer (101) can be given, for example, design by including a filler, which will be described later. In particular, the adhesive can be made to contain a white pigment such as titanium dioxide, making it easier to detect foreign matter that has entered the inner surface of the forming container (1). Considering the balance between these effects and the adhesive strength of the adhesive layer (101), the content of the filler is usually 10 to 60% by weight. The thickness of the adhesive layer (101) is not particularly limited, and is usually 1 to 5 μm.

[0036] The reinforcing layer (10b) is optional and may be made of any of the known polyolefin films (B). By interposing the reinforcing layer (10b) between the heat-sealable resin layer (10a) and the metal foil layer (10c), the mechanical properties of the molded container (1) and the package (2) can be improved. As the polyolefin constituting the polyolefin film (B), various known polyolefins can be used, for example, polyethylene and polypropylene. Examples of polyethylene include high density polyethylene, medium density polyethylene, and linear low density polyethylene. Examples of polypropylene include homopolypropylene, poly(ethylene-propylene) random copolymer, and polyethylene-polypropylene block copolymer. The film made of homopolypropylene may be the same as the homopolypropylene film (A). Both polyethylene and polypropylene may be modified with unsaturated carboxylic acid such as maleic anhydride or vinyl acetate. The means for forming the polyolefin into a film is not particularly limited, and examples thereof include various known (co)extrusion molding methods (inflation, T-die, etc.), stretching methods, lamination methods, etc. In the case of the stretching method, the polyolefin film (B) may be either a stretched type or a non-stretched type. The polyolefin film (B) may contain various known fillers and / or elastomers. Examples of the fillers include clay, silica, talc, titanium dioxide, and carbon black, and two or more of these may be combined. Examples of the elastomers include styrene-based elastomers and / or olefin-based elastomers, and two or more of these may be combined. When the polyolefin film (B) is composed of at least two laminated layers including at least a poly(propylene-ethylene) random copolymer layer and / or a polypropylene-polyethylene block copolymer layer, the formability of the metal laminate packaging material (10) and the impact resistance of the molded container (1) become particularly good. The number of layers of the laminated film may be specifically 2 to 5. Specific examples of the laminated film include two-layer or three-layer polyolefin films in which a poly(ethylene-propylene) random copolymer layer and a polyethylene-polypropylene block copolymer layer are combined in any order. The thickness of the polyolefin film (B), i.e., the thickness of the reinforcing layer (10b), is not particularly limited, but is usually 20 to 300 μm, preferably 30 to 200 μm, from the viewpoints of the formability of the metal laminate packaging material (10) and the durability and impact resistance of the molded container (1) and the package (2).

[0037] An adhesive layer (102) (not shown) may be provided between the reinforcing layer (10b) and the barrier layer (10c). The adhesive for the adhesive layer (102) may be the same as that for the adhesive layer (101), and a two-component curing type polyether-urethane resin adhesive and / or a two-component curing type polyester-urethane resin adhesive is particularly suitable. The adhesive layer (102) may also contain the filler that may be contained in the adhesive layer (101) in the amount described above. The thickness of the adhesive layer (102) is not particularly limited, and is usually about 1 to 5 μm.

[0038] The barrier layer (10c) is a layer for protecting the oil-containing food (3) from gas, water vapor, light, and the like, and is composed of various known metal foils (C). Examples of the metal foils (C) include aluminum foil, iron foil, stainless steel foil, copper foil, and nickel foil. Among these, aluminum foil is preferable in terms of light shielding properties, barrier function, formability, cost, and the like. In addition, since aluminum foil has good ductility, defects such as cracks and pinholes are unlikely to occur in the barrier layer (10c) even if the metal laminate packaging material (10) in which the metal foil (C) is made of aluminum foil is subjected to a forming method involving large deformation such as deep drawing or stretch forming. Examples of the aluminum foil include soft (O material) or hard (H18 material) pure aluminum foil or aluminum alloy foil, and in particular, an Al-Fe alloy foil containing 0.7 to 1.7% iron is preferable. For example, A1000 series or A8000 series soft materials (O materials) specified in JIS H4160 are preferred because they have excellent formability in cold forming such as deep drawing. Examples of the soft materials (O materials) include A8021H-O materials, A8079H-O materials, and A1N30-O materials. The thickness of the metal foil (C), i.e., the thickness of the barrier layer (10c), is not particularly limited, but is usually 50 to 200 μm, preferably 50 to 150 μm, from the viewpoints of the defects of the barrier layer (10c) and the durability and impact resistance of the formed container (1) and the package (2).

[0039] At least one of the two surfaces of the barrier layer (10c) may be provided with a base layer by chemical conversion treatment. This base layer is formed, for example, by applying a water-alcohol solution selected from the following group as a chemical conversion treatment liquid to the surface of the metal foil (C) that has been subjected to a degreasing treatment. (i) a water-alcohol solution containing phosphoric acid, chromic acid, and at least one compound selected from the group consisting of metal salts of fluorides and nonmetal salts of fluorides; (ii) a water-alcohol solution containing phosphoric acid, at least one resin selected from the group consisting of acrylic resins, chitosan derivative resins, and phenolic resins, and at least one compound selected from the group consisting of chromic acid and chromium (III) salts; (iii) A water-alcohol solution containing phosphoric acid, at least one resin selected from the group consisting of acrylic resins, chitosan derivative resins, and phenolic resins, at least one compound selected from the group consisting of chromic acid and chromium (III) salts, and at least one compound selected from the group consisting of metal salts of fluorides and nonmetal salts of fluorides. The amount of the chemical conversion treatment solution used is not particularly limited, and the amount of chromium deposited on one side of the barrier layer (10c) is usually 0.1 to 50 mg / m 2 , preferably 2 to 20 mg / m 2 It is sufficient if the range is such that

[0040] An adhesive layer (103) (not shown) may be provided between the barrier layer (10c) and the protective resin layer (10d). The adhesive for the adhesive layer (103) may be the same as that for the adhesive layer (101), and a two-component curing type polyether-urethane resin adhesive and / or a two-component curing type polyester-urethane resin adhesive is particularly suitable. The adhesive layer (103) may also contain the filler that may be contained in the adhesive layer (101) in the amount described above. The thickness of the adhesive layer (103) is not particularly limited, and is usually about 1 to 5 μm.

[0041] The protective resin layer (10d) is a layer that forms the outermost surface of the formed container (1), ensures the strength of the formed container (1) and the packaging body (2), and protects the oil-containing food (3) contained in the packaging body (2) from the outside, and is composed of various known synthetic resin films (D). Examples of the synthetic resin constituting the synthetic resin film (D) include polyolefin, polyethylene, polyester, polyamide, and other synthetic resins. Examples of the polyolefin include polyethylene and polypropylene. Examples of the polyethylene include high-density polyethylene, medium-density polyethylene, and linear low-density polyethylene. Examples of the polypropylene include homopolypropylene, poly(ethylene-propylene) random copolymer, and polyethylene-polypropylene block copolymer. The film made of homopolypropylene may be the same as the homopolypropylene film (A). Both the polyethylene and the polypropylene may be modified with an acid such as maleic anhydride or vinyl acetate. Examples of the polyester include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, and polybutylene naphthalate. Examples of the polyamide include 6-nylon. Examples of the other synthetic resins include polystyrene, polyvinyl chloride, and polycarbonate. The means for forming the synthetic resin film (D) into a film is not particularly limited, and examples thereof include various known (co)extrusion molding methods (inflation, T-die, etc.), stretching methods, lamination methods, and the like. In the case of the stretching method, the synthetic resin film (D) may be either a stretched type or a non-stretched type. The synthetic resin film (D) may contain the above-mentioned filler and / or the above-mentioned elastomer. When the synthetic resin film (D) is composed of at least two laminated layers including at least a poly(propylene-ethylene) random copolymer layer and / or a polypropylene-polyethylene block copolymer layer, the formability of the metal laminate packaging material (10) and the weather resistance of the molded container (1) are improved. The number of layers of the laminated film may be specifically 2 to 5. Specific examples of the laminated film include two- or three-layer polyolefin films in which a poly(ethylene-propylene) random copolymer layer and a polyethylene-polypropylene block copolymer layer are combined in any order. The surface of the synthetic resin film (D) may be coated with a layer of an overcoat agent made of a thermosetting crosslinkable resin such as epoxy resin, chlorinated polyolefin resin, nitrocellulose, acrylic resin, vinyl chloride-vinyl acetate copolymer, etc. The thickness of the synthetic resin film (D), i.e., the thickness of the protective resin layer (10d), is not particularly limited, but taking into consideration the durability, impact resistance, weather resistance, etc. of the molded container (1) and the packaging body (2), it is usually 15 to 50 μm, preferably 15 to 40 μm.

[0042] The metal laminate packaging material 10 can be produced by various known methods, such as dry lamination, extrusion lamination, and heat lamination. In the case of the dry lamination method, the adhesives described above can be used.

[0043] Preferred embodiments of the metal laminate packaging material (10) are as follows. First embodiment: an embodiment in which the heat-sealable resin layer (10a) is made of a non-oriented homopolypropylene film (thickness 20 to 400 μm, preferably 40 to 350 μm), the barrier layer (10c) is made of an aluminum foil (particularly A8079H-O material or A8021H-O material of JIS H4160) (thickness 50 to 200 μm, preferably 50 to 150 μm) having a base layer formed on at least one side with the chemical conversion treatment liquid, and the protective resin layer (10d) is made of a two-layer or three-layer polyolefin film (total thickness 15 to 50 μm, preferably 15 to 40 μm) in which a poly(ethylene-propylene) random copolymer layer and a polyethylene-polypropylene block copolymer layer are combined in any order. Second embodiment: In the first embodiment, a two-layer or three-layer film (total thickness of 20 to 300 μm, preferably 30 to 200 μm) in which a poly(ethylene-propylene) random copolymer layer and a polyethylene-polypropylene block copolymer layer are combined in any order is interposed between the heat-sealable resin layer (10a) and the protective resin layer (10d) as the reinforcing layer (10b).

[0044] The molded container (1) of the present invention is obtained by processing a metal laminate packaging material (10) by various known molding means. Examples of the molding means include press molding such as stretch molding and deep drawing. In the case of deep drawing, first, the metal laminate packaging material (10) cut to a predetermined size is set on the upper surface of a fixed female mold (die) from the protective resin layer (10d) side. Then, a movable male mold having the same shape as the container part of the molded container (1) is lowered from the heat-sealable resin layer (10a) side of the metal laminate packaging material (10) to perform deep drawing. Next, the movable male mold is raised, and the molded container (1) is removed from the fixed female mold. The flange part (13) of the molded container (1) may be trimmed as necessary to remove unnecessary parts. In this way, a molded container (1) of a desired shape is obtained.

[0045] The shape of the forming container (1) is not particularly limited, and may be appropriately set according to the application and design. For example, the opening (11) may be circular, elliptical, polygonal, etc. The flange portion (13) may be circular, elliptical, polygonal, etc. The side wall (14) may be cylindrical, polygonal, or tapered, and may have a step at the middle position or may be embossed. The bottom wall (15) may be circular, elliptical, polygonal, etc., like the opening (11). The overall shape of the forming container (1) is not limited to a cup shape as shown in FIG. 2, and may be, for example, a tray shape. The dimensions of the forming container (1) are also not particularly limited. In the case of a cup-shaped forming container (1) as shown in FIG. 2, for example, the width of the flange portion (13) is about 5 to 10 mm, and the ratio (D / H) of the diameter (R) of the opening (11) to the container depth (D) is about 2.

[0046] The method of forming the notch (16) for opening is not particularly limited, and for example, a ring-shaped notch forming blade (not shown) heated to about 200°C is pressed against the upper surface of the flange portion (13) to cause the blade tip to penetrate into the heat-sealable resin layer (10a), and then pulled up to leave a notch (16) for opening with the same cross-sectional shape as the blade tip. Examples of notch forming blades include those described in JP-A-2017-30087 and JP-A-7-20004. The position of the notch (16) for opening is not particularly limited, and when the width of the flange portion (13) is 5 to 10 mm, it may be, for example, usually 2 to 4 mm from the periphery (12) of the opening (11).

[0047] The package (2) of the present invention is obtained by placing an oil-containing food (3) in the molded container (1) and then heat-sealing the lower surface of the lid (4) to the upper surface of the flange portion (13).

[0048] The package (2) is opened by the interfacial peeling that occurs between the heat-sealable resin layer (40d) on the lower surface of the lid (4) and the heat-sealable resin layer (10a) of the molded container (1). Fig. 3(a) is a partial cross-sectional view of the package (2) of the present invention, in which an annular heat-sealed portion (51) is formed between the lower surface of the lid (4) and the upper surface of the flange portion (13) of the formed container (1) by the heat fusion. Meanwhile, an annular non-heat-sealed portion (52) is formed on the outer periphery (opposite the opening (11)) of the heat-sealed portion (51), which can be used as a hook for opening. The width of the non-heat-sealed portion (52) is not particularly limited, but is usually 1 to 3 mm when the width of the flange portion (13) is 5 to 10 mm. In this case, the width of the heat-sealed portion (51) is usually 7 to 9 mm. In the package (2) of FIG. 3(b), a notch (16) for opening is formed at a position slightly away from the opening (11) of the molded container (1). The position of the notch (16) is not particularly limited, and when the width of the flange portion (13) is 5 to 10 mm, the notch may be located, for example, 2 to 4 mm from the periphery (12) of the opening (11). In this case, the width of the heat-sealed portion (51) is usually 6 to 8 mm. The cross section of the notch (16) is usually substantially V-shaped, but may be, for example, substantially U-shaped. When the notch (16) is substantially V-shaped, the angle formed by both oblique sides is not particularly limited, and is usually 5° to 25°. The position of the tip of the notch (16) is not particularly limited, and may be reached to the heat-sealable resin layer (10a) or the reinforcement layer (10b). When the tip reaches near the barrier layer (10c) (not shown), even if the peeling of the lid (4) progresses due to cohesive failure of the heat-sealable resin layer (10a) or the reinforcing layer (10b), this progress always stops at the position of the opening notch (16), making it easier to open.

[0049] Examples of fat-containing foods (3) include semi-solid or solid processed foods containing animal or vegetable oils, such as curry roux, pasta sauce, stew, demi-glace sauce, processed fish foods (tuna, mackerel, saury, sardines, etc., pickled or boiled in oil), peanut butter, and processed meat products (corned beef, Spam, etc.).

[0050] The lid (4) is a sealing means for the oil-containing food (3) contained in the formed container (1), and is made of a laminated packaging material (40). 3(a) and 3(b), the laminate packaging material (40) is formed by laminating a predetermined protective resin layer (40a), a metal foil layer (40b), a reinforcing layer (40c), and a heat-sealable resin layer (40d) in this order. However, both the metal foil layer (40b) and the reinforcing layer (40c) are optional and can be omitted. The protective resin layer (40a) is a layer forming the outermost surface of the lid (4) and is composed of various known synthetic resin films. As the synthetic resin film, those listed as the synthetic resin film (D) can be used, and a film selected from a stretched polypropylene film, a stretched polyethylene terephthalate film, and a stretched polyamide film is preferable. The protective resin layer (40a) may be a multilayer in which one or more of the same or different synthetic resin films are combined in any order. The protective resin layer (40a) may be composed of the above-mentioned overcoat agent. The thickness of the protective resin layer (40a) is not particularly limited, but is usually 1 to 30 μm from the viewpoint of durability, impact resistance, weather resistance, etc. of the package (2). The optional metal foil layer (40b) functions as a barrier layer for protecting the oil-containing food (3) contained in the forming container (1) from gas, water vapor, light, and the like. The same metal foil as the metal foil (C) can be used as the metal foil, and aluminum foil is preferable. The aluminum foil can be a pure aluminum foil or an aluminum alloy foil of O material or H18 material. A base layer made of the chemical conversion treatment liquid may be formed on at least one of the two surfaces of the metal foil layer (40b). The thickness of the metal foil layer (40b) is not particularly limited, and is usually 5 to 40 μm. The optional reinforcing layer (40c) is made of various known synthetic resin films, and by being interposed between the metal foil layer (40b) and the heat-sealable resin layer (40d), the strength of the lid (4) can be improved. Examples of the synthetic resin film include the polyolefin film (B), as well as the polyester film and the polyamide film. The reinforcing layer (40c) may be a composite film of two or more layers of synthetic resin films. The thickness of the reinforcing layer (40c) is not particularly limited, and is usually 5 to 30 μm. The heat-sealable resin layer (40d) is a layer that is heat-sealed to the heat-sealable resin layer (10a) that constitutes the upper surface of the flange portion (13) of the molded container (1), and is composed of various known thermoplastic resin films. Specific examples include the polyethylene film and polypropylene film listed as the polyolefin film (B), as well as polyvinyl alcohol film, ionomer resin film, and acrylic copolymer resin film. The thermoplastic resin film may contain the above-mentioned filler and / or elastomer. The heat-sealable resin layer (40c) may be a multilayer formed by combining one or more of the same or different thermoplastic resin films in any order. The thickness of the heat-sealable resin layer (40d) is not particularly limited, and is usually 10 to 100 μm. The laminate packaging material 40 can be produced by, for example, a dry lamination method, an extrusion lamination method, a heat lamination method, etc. In the case of the dry lamination method, the above-mentioned adhesives can be used as interlayer adhesives.

[0051] The lid (4) is made by processing a laminated packaging material (40) into a desired shape. The shape of the lid (4) is not particularly limited, and may be the same or similar to the flange portion (13) of the formed container (1). The lid (4) may be provided with an opening tab as desired, and the size and shape of the opening tab are not particularly limited. Examples of the shape include a semicircle, a triangle, and a rectangle. The opening tab may be a part of the laminated packaging material (40) that constitutes the lid (4). A separately manufactured tab may be attached to a part of the outer periphery of the lid (4).

[0052] The method for producing the package (2) is not particularly limited, and various known methods can be used. Taking the molded container (1) of Fig. 2 as an example, after a predetermined amount of oil-containing food (3) is placed in this molded container (1), a lid (4) of a predetermined shape is placed on the upper surface of the flange portion (13) from the heat-sealable resin layer (40d) side, and an annular heat sealer heated to a predetermined temperature is pressed against the upper surface of the flange portion (13) with a predetermined pressure for a predetermined time, so that the heat-sealable resin layer (40d) forming the lower surface of the lid (4) and the heat-sealable resin layer (10a) forming the upper surface of the flange portion (13) of the molded container (1) are heat-sealed to obtain the package (2). The edge of the lid (4) may be trimmed as necessary. The packages (2) in Figures 3(a) and (b) have in common an annular heat-sealed portion (51) formed between the bottom surface of the lid (4) and the top surface of the flange portion (13) in the circumferential direction of the flange portion (13). However, in the case of the package (2) in Figure 3(a), a non-heat-sealed portion (52) of a predetermined width is formed on the outside of the heat-sealed portion (51), which can be used as a cut-out for opening. Also, in the case of the package (2) in Figure 3(b), a cut-out notch (16) of a predetermined shape is formed on the inside of the heat-sealed portion (51), which can be used as a cut-out for opening.

[0053] The package (2) serves as a storage container, cooking utensil and tableware, and is therefore convenient for the oil-containing food (3) to be heated, opened and then eaten as is. EXAMPLES

[0054] The present invention will be further described below with reference to examples and comparative examples, but the technical scope of the present invention is not limited thereto.

[0055] The abbreviations used in the present examples have the following meanings. Tmp(℃): Melting point (JIS K7121-1987) ΔH(J / g): Crystal melting energy (JIS K7122-1987) TYS(MPa): Tensile yield stress (JIS K7127) HPP1-3: Homopolypropylene rPP: Poly(ethylene-propylene) random copolymer bPP: Poly(ethylene-propylene) block copolymer LLDPE: Linear low density polyethylene PET: Polyethylene terephthalate PU adhesive: Two-component curing polyester-polyurethane adhesive

[0056] The melting point (Tmp ° C.) and the crystal melting energy (ΔH J / g) were measured under the following conditions. Measurement equipment: Shimadzu Corporation's differential scanning calorimeter "DSC-60A" Sample size: 5mg ·Measurement temperature: 23℃~210℃ Heating rate: 10℃ / min

[0057] Tensile yield stress (TYS) was measured using a Tensilon RTG-1210 manufactured by A&D Co., Ltd.

[0058] Table 1 shows the melting points, crystalline melting energies and tensile yield stresses of HPP1, HPP2, HPP3, rPP, bPP and LLDPE.

[0059] [Table 1]

[0060] 1. Preparation of aluminum laminate packaging material Manufacturing Example 1 Both sides of a 120 μm thick aluminum foil (A8079H-O material) were treated with a chemical conversion solution consisting of phosphoric acid, acrylic resin, a chromium (III) salt compound, water and alcohol to produce a treated aluminum foil with a base layer. The amount of chromium deposited on each side was 10 mg / m 2Next, a PU adhesive was applied to one side of the treated aluminum foil so that the dry film thickness was 3 μm, and a film made of HPP1 (300 μm thick, produced by the T-die method) was laminated. Next, a PU adhesive was applied to the other side of the treated aluminum foil so that the dry film thickness was 3 μm, and a non-oriented three-layer co-extruded polyolefin film having a total thickness of 30 μm, consisting of a 4.5 μm thick rPP layer, a 21 μm thick bPP layer, and a 4.5 μm thick rPP layer, was laminated to produce a laminate. Next, this laminate was aged at 40 ° C for 8 days to produce aluminum laminate packaging material A.

[0061] Manufacturing Examples 2-3 Aluminum laminate packaging materials B and C were produced in the same manner as in Production Example 1, except that a film made of HPP2 (300 μm thick, produced by the T-die method) or a film made of HPP3 (300 μm thick, produced by the T-die method) was used instead of the film made of HPP1.

[0062] Production Example 4 A PU adhesive was applied to one side of the treated aluminum foil of Production Example 1 so that the dry thickness was 3 μm, and a 30 μm thick film made of rPP was laminated. Next, a PU adhesive was applied to the surface of this rPP film so that the dry thickness was 3 μm, and an HPP1 film was laminated. Next, a PU adhesive was applied to the other side of the treated aluminum foil so that the dry thickness was 3 μm, and a three-layer coextruded polyolefin film of Production Example 1 was laminated to produce a laminate. Next, this laminate was aged under the same conditions as Production Example 1 to produce aluminum laminate packaging material D.

[0063] Manufacturing Examples 5-6 Aluminum laminate packaging materials E and F were produced in the same manner as in Production Example 4, except that the HPP1 film was replaced with the HPP2 film or HPP3 film.

[0064] Production Example 7 A PU adhesive was applied to one side of the treated aluminum foil of Production Example 1 so that the dry thickness was 3 μm, and a two-layer coextruded polyolefin film consisting of a 150 μm-thick bPP layer and a 25 μm-thick rPP layer with a total thickness of 175 μm was bonded as a reinforcing layer. Next, a PU adhesive was applied to this two-layer coextruded polyolefin film so that the dry thickness was 3 μm, and an HPP1 film was bonded. Next, a PU adhesive was applied to the other side of the treated aluminum foil so that the dry thickness was 3 μm, and a three-layer coextruded polyolefin film of Production Example 1 was bonded to it to produce a laminate. Next, this laminate was aged under the same conditions as in Production Example 1 to produce an aluminum laminate packaging material G.

[0065] Manufacturing Examples 8-9 Aluminum laminate packaging materials H and I were produced in the same manner as in Production Example 7, except that the HPP1 film was replaced with the HPP2 film or the HPP3 film.

[0066] Comparative Manufacturing Example 1 A PU adhesive was applied to one side of the treated aluminum foil of Production Example 1 so that the dry thickness was 3 μm, and the rPP film (30 μm thick) of Production Example 4 was laminated as a reinforcing layer. Next, a PU adhesive was applied to the other side of the treated aluminum foil so that the dry thickness was 3 μm, and a laminate was produced by laminating the three-layer coextruded polyolefin film of Production Example 1. Next, the laminate was aged under the same conditions as in Production Example 1 to produce aluminum laminate packaging material J.

[0067] Comparative Manufacturing Example 2 A PU adhesive was applied to one side of the treated aluminum foil of Production Example 1 so that the dry thickness was 3 μm, and the two-layer coextruded polyolefin film of Production Example 7 was laminated as a reinforcing layer. Next, a PU adhesive was applied to the other side of the treated aluminum foil so that the dry thickness was 3 μm, and the three-layer coextruded polyolefin film of Production Example 1 was laminated to produce a laminate. Next, this laminate was aged under the same conditions as Production Example 1 to produce aluminum laminate packaging material K.

[0068] Comparative Manufacturing Example 3 A PU adhesive was applied to one side of the treated aluminum foil of Production Example 1 so that the dry thickness was 3 μm, and a 50 μm thick film made of LLDPE was laminated as a reinforcing layer. Next, a PU adhesive was applied to the other side of the treated aluminum foil so that the dry thickness was 3 μm, and a laminate was produced by laminating the three-layer coextruded polyolefin film of Production Example 1. Next, this laminate was aged under the same conditions as in Production Example 1 to produce aluminum laminate packaging material L.

[0069] 2. Preparation of Molded Container Example 1 Aluminum laminate packaging material A was set in a commercially available press die machine, and was drawn and then trimmed to produce a cup-shaped molded container A as shown in Figure 2. Molded container A had a flange outer diameter of 86 mm, a flange width of 10 mm, an opening diameter of 66 mm, a height of 30 mm, and a bottom diameter of 56 mm.

[0070] Examples 2 to 6 Formed containers B to F having the same dimensions as formed container A were produced in the same manner as in Example 1, except that aluminum laminate packaging material B to F were used instead of aluminum laminate packaging material A.

[0071] Example 7 A molded container having the same dimensions as the molded container A was produced in the same manner as in Example 1, except that aluminum laminate packaging material G was used instead of aluminum laminate packaging material A. Next, an annular notch forming blade heated to 200°C was pressed against the upper surface of the flange of this molded container with a pressure of 120 kgf for 2 seconds to carve an annular opening notch having a substantially V-shaped cross section at a position 2 mm away from the periphery of the opening, thereby producing molded container G. The notch had a depth of 110 μm, and its tip was considered to reach the bPP film layer forming the reinforcing layer, as shown in FIG. 3(b).

[0072] Examples 8 to 9 Formed containers H and I were produced in the same manner as in Example 7, except that aluminum laminate packaging material H or I was used instead of aluminum laminate packaging material G. The dimensions of each were the same as those of formed container A, and the shape and dimensions of the opening notch formed on the upper surface of each flange portion were also the same as those of formed container A.

[0073] Comparative Examples 1 to 3 Formed containers J, K and L were produced in the same manner as in Example 1, except that aluminum laminate packaging material J, K or L was used instead of aluminum laminate packaging material A.

[0074] Table 2 shows the layer structures of the molded containers A to L.

[0075] [Table 2]

[0076] 3. Making the Lid Manufacturing Example 10 Both sides of a 12 μm thick aluminum foil (A8021-H18 material) were chemically treated with the coating liquid of Production Example 1 to produce a treated aluminum foil having a base layer. The amount of chromium deposited on each side was 10 mg / m 2 Next, PU adhesive was applied to one side of the treated aluminum foil so that the dry film thickness was 3 μm, and a biaxially stretched PET film with a thickness of 25 μm was laminated. Next, PU adhesive was applied to the other side of the treated aluminum foil so that the dry film thickness was 3 μm, and a 50 μm thick LLDPE film was laminated as a heat-sealing resin to produce a laminate. Next, the laminate was aged at 40°C for 8 days to produce a laminated packaging material. Next, the laminated packaging material was cut into a square of 120 mm x 120 mm to produce lid A.

[0077] Manufacturing Example 11 A PU adhesive was applied to one side of the treated aluminum foil of Production Example 10 so that the dry film thickness was 3 μm, and a biaxially stretched PET film having a thickness of 25 μm was bonded to the treated aluminum foil as a protective resin layer. Next, a PU adhesive was applied to the other side of the treated aluminum foil so that the dry film thickness was 3 μm, and a biaxially stretched PET film having a thickness of 12 μm was bonded to the reinforced layer. Next, a PU adhesive was applied to the biaxially stretched PET film of the reinforced layer so that the dry film thickness was 3 μm, and a LLDPE film having a thickness of 50 μm was bonded to the heat-sealable resin layer to produce a laminate. Next, a laminate was produced by aging the laminate under the same conditions as in Production Example 10. Next, the laminate was cut into a square of 120 mm × 120 mm to produce a lid B.

[0078] 4. Preparation of packaging Example 10 Two molded containers A were prepared. In one molded container A, 20 g of a commercially available retort curry roux (House Foods Co., Ltd., Pro Quality Beef Curry (registered trademark), medium hotness) was placed without ingredients, and a lid A was placed on the flange. Next, a ring sealer (outer diameter 84 mmφ, inner diameter 72 mmφ, width 6 mm) heated to 190°C was pressed against the flange at 0.2 MPa for 2 seconds so that the center of the opening was on the same vertical line as the center of the opening of the molded container A, thereby producing a package A containing curry roux. In the other molded container A, 20 ml of water was placed, and the lid A was heat-sealed to the flange in the same manner and under the same conditions, thereby producing a package A containing water. In each package A, a 6 mm-wide band-shaped area extending in the circumferential direction on the inner side of the upper surface of the flange constituted a heat-sealed portion, and the outer 1 mm-wide unheat-sealed portion was used as an opening hook. Furthermore, a 3 mm wide non-thermally sealed area was formed on the inside of the upper surface of the flange.

[0079] Examples 11 to 15 For molded containers B to F, curry roux-containing packages B to F and water-containing packages B to F were produced in the same manner as in Example 10. Each package had the same dimensions and number of heat-sealed and non-heat-sealed parts as package A.

[0080] Example 16 Two molded containers G were prepared. In one molded container G, 20 g of the retort curry roux, excluding ingredients, was placed, and a lid B was placed on the flange. Next, a ring sealer (outer diameter 86 mmφ, inner diameter 72 mmφ, width 7 mm) heated to 190°C was pressed against the flange at 0.2 MPa for 2 seconds so that the center of the opening was aligned vertically with the center of the opening of the molded container G, to produce a package G containing curry roux. In the other molded container G, 20 ml of water was placed, and a lid B was heat-sealed to the flange in the same manner and under the same conditions to produce a package G containing water. In each package G, a 7 mm-wide band-shaped area extending in the circumferential direction on the outer side of the upper surface of the flange constituted a heat-sealed portion, and there was no unheat-sealed portion on the outer side. In addition, a 3 mm-wide unheat-sealed portion was formed on the inner side of the upper surface of the flange, and an opening notch was formed in this unheat-sealed portion.

[0081] Examples 17 and 18 For the molded containers H and I, curry roux-containing packages H and I and water-containing packages H and I were prepared in the same manner as in Example 16. Each package had the same dimensions and number of heat-sealed and non-heat-sealed parts as package G.

[0082] Comparative Examples 4 to 6 Regarding molded containers J to L, curry roux-containing packages J to L and water-containing packages J to L were produced using lid A in the same manner as in Example 10. Each package had the same dimensions and number of heat-sealed and non-heat-sealed parts as package A.

[0083] 5. Evaluation of packaging 5-1. Easy to open, color and odor resistant Package A containing curry roux was left at room temperature for four weeks, then tilted at 45 degrees and set in a commercially available tensile tester, and the strength of lid A when pulled upward was measured, which was approximately 20 N. Next, the curry roux was discarded from the opened molded container A, the inside was washed, and then wiped with a cloth to check the side walls and bottomThe coloring of the walls and corners and the lingering aroma inside the storage portion of the molded container A were subjected to a sensory evaluation according to the following criteria. The curry roux-containing packages B to L were also subjected to the same sensory evaluation. The results are shown in Table 3.

[0084] ○: Neither coloring of the inside of the container nor lingering odor was observed. △: Slight coloring was observed only in the corners of the inside of the container. No lingering fragrance was observed. ×: Of the inside of the container bottom Strong staining was observed on the walls and corners. A lingering fragrance was also observed.

[0085] [Table 3]

[0086] 5-2. Presence or absence of defects in heat-sealed parts during heat treatment After the water-filled package A was heated in a retort oven (125°C, 20 minutes), the heat-sealed portion was visually observed from the side of the flange, and no defects such as delamination or peeling were found. The same evaluation was carried out on the water-filled packages B to L, and no defects were found.

[0087] As shown in Table 3, all of the packages A to I of the examples had good resistance to coloring and odor transfer, and the opening strength was also satisfactory, since the innermost surface of the molded container, which is the main body, was formed from a homopolypropylene film. On the other hand, all of the packages J to L of the comparative examples had good opening strength, but poor resistance to coloring and odor transfer, since the innermost surface of the molded container, which is the main body, was formed from a polyolefin other than homopolypropylene. [Industrial Applicability]

[0088] The molded container of the present invention is suitable for long-term storage of foods containing fats and oils, such as curry, stew, and pasta sauce. [Explanation of symbols]

[0089] (10) metal laminate packaging material, (10a) heat-sealable resin layer, (10b) reinforcing layer, (10c) barrier layer, (10d) protective resin layer, (A) homopolypropylene film, (B) polyolefin film, (C) metal foil, (D) synthetic resin film, (1) molded container, (11) opening, (12) rim, (13) flange portion, (14) side wall, (15) bottom wall, (16) opening notch, (2) package, (3) oil-containing food, (4) lid, (40) laminate packaging material, (40a) protective resin layer, (40b) metal foil layer, (40c) reinforcing layer, (40d) heat-sealable resin layer, (51) heat-sealed portion, (52) non-heat-sealed portion

Claims

[Claim 1] A molded container made of a metal laminate packaging material for storing oil-containing food, The housing has an opening and a flange portion formed in an annular shape on a periphery of the opening, The metal laminate packaging material has a heat-sealable resin layer made of a homopolypropylene film, a barrier layer made of a metal foil, and a protective resin layer made of a synthetic resin film, The heat-sealable resin layer forms an innermost surface of the container, and the protective resin layer forms an outermost surface of the container. Molded container.

Images