JP6590520B2 - Hot beverage container lid and packaging - Google Patents

Description

The present invention relates to a package formed by filling and packaging a hot beverage in a container, and a lid used for the container of the package.
In this specification and claims, “hot beverage” refers to a beverage sold in a heated state such as coffee, black tea, Japanese tea, lemonade, ginger hot water, soup flour, amazake, and soup.

Conventionally, metal cans are generally used as containers for filling and packaging hot beverages such as coffee. And the packaging body of the hot beverage packaged by the metal can is placed at a predetermined temperature (for example, about 50 to 60 ° C.) in a showcase with a heating device called a can warmer installed in a store such as a supermarket or a convenience store. ) Was displayed and stored in a heated state for sale.
However, in the case of a hot beverage package using a metal can, the metal can has good thermal conductivity, so it may become too hot to hold in the heated state and be heavy. Furthermore, there was a problem in terms of easy disposal.

Accordingly, in recent years, plastic bottles have been used as hot beverage containers that replace metal cans.
However, since the polyethylene terephthalate resin which comprises a PET bottle has oxygen permeability, the oxidation of the content is accelerated | stimulated by heating and there exists a possibility that quality may deteriorate.
For this reason, in a plastic bottle for hot beverages, measures are taken to prevent the deterioration of the quality of the contents accompanying heating by increasing the thickness of the plastic bottle or by providing an oxygen barrier layer.
However, in the case of PET bottles, there is a limit to increasing the oxygen barrier property by the above-mentioned means, and since it does not have a light shielding property, it cannot be said that it is sufficient in terms of maintaining the quality of the contents. .

On the other hand, a chilled beverage container is known which is composed of a cup-shaped container body and a lid material that is heat-sealed to the flange portion of the container body. Examples of the container body include a cup-shaped laminate sheet in which a thermoplastic resin layer such as polyethylene terephthalate resin is laminated on the inner surface of a paper layer, and a thermoplastic resin molded product such as polyethylene resin and polypropylene resin. It is used. In addition, as a lid material, a two-layer structure in which a sealing material such as an unstretched polypropylene resin (CPP) film is bonded and laminated on the inner surface of an aluminum foil, or an outer resin layer such as a polyethylene terephthalate resin film on the outer surface of the aluminum foil The thing of the 3 layer structure which laminated | stacked is used.
And in the following patent document 1, as a hot beverage container, like the above-mentioned chilled beverage container, it is composed of a cup-shaped container body and a lid material that is heat-sealed to the flange portion of the container body. Has been proposed.
According to the packaging body in which the hot beverage is filled and packaged with the container of the above form, since the container body has heat insulation properties, it is not hot even if it is held in the warmed state, and is lightweight and easy to dispose. In addition, if a material having a barrier property or a light-shielding property is used as the material of the container main body and the lid member, the quality maintaining function of the contents can be enhanced.

JP2015-54703A

  However, in the case of a package filled and packaged with a hot beverage by the container consisting of the container body and the lid described above, when heated in a showcase with a heating device, etc., the aluminum foil and the sealing material constituting the lid There was a problem that delamination occurred between them and the sealing function of the container was impaired.

  An object of the present invention is to provide a lid for a hot beverage container that does not cause delamination with heating, and by filling and packaging a hot beverage using a container comprising the lid and the container body. An object of the present invention is to provide a package body that is not heated even when held in a heated state, is light in weight, is easy to dispose, and has a high content quality maintaining function.

  In order to achieve the above object, the present invention comprises the following aspects.

1) A lid that is heat-sealed to the flange portion of the container body so as to cover the opening of the container body filled with hot beverage as a content, and is adhesively laminated to the metal foil layer and the inner surface of the metal foil layer A cover material for a hot beverage container, wherein a base treatment layer made of a chemical conversion film is formed in advance on the inner surface of the metal foil layer.

2) The lid material for a hot beverage container according to 1) above, wherein the chemical conversion film is formed by subjecting the surface of the metal foil to a chromate treatment or a non-chromium chemical conversion treatment using a zirconium compound.

3) The lid material for hot beverage containers according to 1) or 2) above, further comprising an outer resin layer laminated on the outer surface of the metal foil layer.

4) A lid material is heat-sealed to the flange portion of the container main body so as to cover the opening of the container main body filled with the hot beverage, and the lid material is any one of the above 1) to 3). A package comprising two lids for hot beverage containers.

When using a container consisting of a container body and a lid material for packaging hot beverages, the metal foil layer and the sealing material constituting the lid material are affected by heat when heated in a state where the beverage is filled and sealed in the container. When the internal pressure generated by the thermal expansion of the air present in the head space in the container in this state is reduced, the seal part between the flange part of the container body and the lid member and its It is considered that delamination occurs in the cover material in the peripheral portion.
According to the lid material for hot beverage containers of 1) above, the adhesive strength between the metal foil layer and the sealing material layer accompanying heating is reduced by the base treatment layer made of a chemical conversion film formed in advance on the inner surface of the metal foil layer. Therefore, it is possible to effectively prevent peeling between the metal foil layer and the sealing material layer.

  According to the lid material for hot beverage containers of 2) above, the chemical conversion film constituting the base treatment layer is formed by subjecting the surface of the metal foil to a chromate treatment or a non-chromium chemical conversion treatment using a zirconium compound. In addition, it is easy to form a base treatment layer, and an excellent delamination preventing effect can be obtained.

  According to the lid material for hot beverage containers of 3) above, since the outer resin layer is laminated on the outer surface of the metal foil layer, the heat insulating property of the lid material is improved, and the expansion of the lid material with heating is increased. It is suppressed.

  According to the packaging body of 4) above, the container for filling and packaging the hot beverage is constituted by the container body and the lid material, and there is no possibility that delamination occurs in the lid material with heating. As a body, even if it is held in a heated state, it is not hot, lightweight, easy to dispose, and further equipped with a high content quality maintaining function can be put to practical use.

It is a semi-cut plane view of the package which concerns on 1st Embodiment of this invention. It is sectional drawing which expands and shows a part of package body of FIG. It is a semi-cut plane view of the package which concerns on 2nd Embodiment of this invention. It is sectional drawing which expands and shows a part of package body of FIG.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

<First Embodiment>
1 and 2 show a first embodiment of the present invention.
The package body (1A) according to this embodiment has a lid on the flange portion of the container body (2A) so as to cover the opening of the container body (2A) filled with hot beverage (C) such as coffee. The material (3A) is heat-sealed.

The container body (2A) is cup-shaped and opened upward, and is made of a resin molded product.
The trunk portion (21) of the container body (2A) has a tapered cylindrical shape with a diameter gradually increasing upward.
The bottom part (22) provided continuously to the lower end edge of the trunk part (21) has an outer peripheral part that is flat, and an inner peripheral part that is raised upwardly in a trapezoidal shape. Yes.
The flange part (23) is projected substantially horizontally from the upper end edge of the body part (21) outward in the radial direction.
As a material of the container body (2A), for example, a thermoplastic resin such as a polypropylene resin, a polystyrene resin, or a polyethylene resin is used. The container body (2A) is formed by, for example, vacuum forming or pressure forming, but is not limited to these methods.

  As shown in FIG. 2, the lid (3A) includes a metal foil layer (301), a sealing material layer (302) bonded and laminated on the inner surface (lower surface) of the metal foil layer (301), a metal foil layer ( 301) and an outer resin layer (303A) laminated on the outer surface (upper surface). A base treatment layer (304) made of a chemical conversion film is formed in advance on the lower surface of the metal foil layer (301).

The metal foil layer (301) imparts barrier properties, light shielding properties, thermal conductivity, etc. to the lid material (3A), and is composed of, for example, aluminum foil, stainless steel foil, copper foil, nickel foil, etc. Preferably, an aluminum foil is used.
In the case of an aluminum foil, it may be either a pure aluminum foil or an aluminum alloy foil, and may be either soft or hard. For example, if it is an annealed A8021 (O material) classified by JIS H4160, Since generation | occurrence | production of a wrinkle is also suppressed, it can use suitably.
The thickness of the metal foil layer (301) is preferably 6 μm to 100 μm. By setting the thickness of the metal foil layer (301) to 6 μm or more, pinholes and tears can be prevented from occurring during rolling or heat-sealing when manufacturing the metal foil. By setting the thickness of the layer (301) to 100 μm or less, an increase in weight and material cost can be suppressed.

Adhesion between the metal foil layer (301) and the sealing material layer (302) during heating by pre-forming a base treatment layer (304) made of a chemical conversion coating on the inner surface (lower surface) of the metal foil layer (301) A decrease in strength is suppressed.
The chemical conversion film is a film formed by performing a chemical conversion treatment on the surface of the metal foil, and preferably formed by subjecting the surface of the metal foil to a chromate treatment or a non-chromium chemical conversion treatment using a zirconium compound. Is done.
For example, in the case of chromate treatment, an aqueous solution of any one of the following 1) to 3) is applied to the surface of the metal foil that has been degreased and then dried.
1) Mixture of phosphoric acid, chromic acid, and at least one of fluoride metal salt and fluoride nonmetal salt 2) Of phosphoric acid, acrylic resin, chitosan derivative resin and phenolic resin 3) a mixture of at least one of chromic acid and chromium (III) salt, 3) phosphoric acid, one of acrylic resin, chitosan derivative resin, phenolic resin, chromic acid and chromium (III ) A mixture of at least one of the salts and at least one of a fluoride metal salt and a fluoride non-metal salt. The chemical conversion film preferably has a chromium adhesion amount in the range of 0.1 to 50 mg / m ^2. In particular, the range of ^{2 to} 20 mg / m ² is preferable. With the chemical film having such a chromium adhesion amount, it is possible to effectively prevent a decrease in adhesive strength due to heating.
The lid material (3A) of the present invention forms a base treatment layer made of a chemical conversion film not only on the inner surface (lower surface) of the metal foil layer (301) but also on the outer surface (upper surface) of the metal foil layer (301). It may be what you did.

The sealing material layer (302) constituting the innermost layer of the lid material (3A) imparts heat sealing (heat seal) properties to the lid material (3A), and the metal foil layer (301) is added to the contents (C). It plays the role of protecting from
As the material of the sealing material layer (302), an unstretched thermoplastic resin film is preferably used. The type of unstretched thermoplastic resin film used as the sealing material layer (302) is not particularly limited, but in terms of content resistance and heat sealability, polyethylene resin, polypropylene resin, olefin copolymer Resins and those composed of these acid-modified products or ionomers are preferred. Here, examples of the olefin copolymer resin include ethylene / vinyl acetate copolymer (EVA) resin, ethylene / acrylic acid copolymer (EAA) resin, and ethylene / methacrylic acid copolymer (EMMA) resin. can do. A polyamide resin film (for example, 12 nylon resin film) or a polyimide resin film can also be used as the sealing material layer (302).
The sealing material layer (302) can be blended with a lubricant and / or solid fine particles in order to enhance the surface slipperiness.
The thickness of the sealing material layer (302) is preferably set to 20 μm to 80 μm. By setting the thickness of the sealing material layer (302) to 20 μm or more, the occurrence of pinholes can be sufficiently prevented, and by setting the thickness of the sealing material layer (302) to 80 μm or less, It is possible to reduce the cost by reducing the amount of resin used. In particular, the thickness of the sealing material layer (302) is particularly preferably set to 30 μm to 50 μm.
The sealing material layer (302) may be a single layer or multiple layers. Examples of the multilayer sealing material layer (302) include a three-layer film in which random polypropylene resin films are laminated on both sides of a block polypropylene resin film.

The outer resin layer (303A) constituting the outermost layer of the lid material (3A) provides heat insulation to the lid material (3A) and also functions to protect the surface of the metal foil layer (301) and the printing surface. It can be.
The outer resin layer (303A) of this embodiment is formed by adhesively laminating a film such as a polyester resin film or a polyamide resin film on the outer surface of the metal foil layer (301). A stretched film is preferably used as the film. Among these, in terms of heat resistance and strength, a biaxially stretched polyester resin film, a biaxially stretched polyamide resin film, or a multilayer film containing these is preferable, and a biaxially stretched polyester resin film and a biaxially stretched polyamide resin film You may use the multilayer film in which was bonded. Although the kind of polyamide resin film is not specifically limited, For example, 6 nylon resin film, 6, 6 nylon resin film, MXD nylon resin film etc. are mentioned. Examples of the biaxially stretched polyester resin film include a biaxially stretched polybutylene terephthalate (PBT) resin film and a biaxially stretched polyethylene terephthalate (PET) resin film. When laminating these films, for example, it is performed via an adhesive by a dry laminating method.
The thickness of the outer resin layer (303A) is preferably 0.5 μm to 38 μm. By setting the thickness of the outer resin layer (303A) to 0.5 μm or more, sufficient strength as the lid material (3A) can be secured, and the thickness of the outer resin layer (303A) is 38 μm. By setting to the following, functions such as heat insulation, surface protection, and design can be economically exhibited without impairing heat-fusibility.

The adhesive layer (305) is a layer responsible for joining the metal foil layer (301) and the sealing material layer (302) and joining the metal foil layer (301) and the outer resin layer (303A).
These adhesive layers (305) are formed of, for example, a polyurethane resin adhesive, an acrylic resin adhesive, an epoxy resin adhesive, a polyolefin resin adhesive, an elastomer adhesive, a fluorine adhesive, or the like. . Among them, it is preferable to use an adhesive containing a two-component curable polyester-urethane resin or a polyether-urethane resin using a polyester resin as a main agent and a polyfunctional isocyanate compound as a curing agent.
The thickness (film thickness) of the adhesive layer (305) is about 1 to 15 μm, but it is preferably 2 to 5 μm in view of improvement in adhesion and formability.

<Second Embodiment>
3 and 4 show a second embodiment of the present invention.
The package (1B) according to this embodiment is the same as the package (1A) of the first embodiment shown in FIGS. 1 and 2 except for the following points.
That is, in the package (1B) of the second embodiment, the container main body (2B) is a metal foil layer (201) and a heat-fusible resin layer (on the inner surface of the metal foil (201)) ( 202) and a laminated sheet (200) composed of a heat resistant resin layer (203) laminated on the outer surface of the metal foil (201) is formed by press molding (see FIG. 4). The press forming of the laminated sheet (200) is performed by cold forming such as deep drawing forming or stretch forming.
The body (21) of the container body (2B) is formed with a step (211) at a height near the upper end, and the upper part of the step (211) is formed in a short cylindrical shape. The portion below (211) has a tapered cylindrical shape whose diameter gradually decreases toward the bottom (22), and a large number of ridge lines (212) extending in the vertical direction are formed at equal intervals in the circumferential direction. It has a substantially regular polygonal cross section.
Further, the flange portion (23) of the container body (2B) has a tip edge portion (231) curled into a circular cross section.
The metal foil layer (201) imparts barrier properties, light shielding properties, thermal conductivity, etc. to the container body (2B), and is composed of, for example, aluminum foil, stainless steel foil, copper foil, nickel foil, etc. However, preferably, an aluminum foil is used. Furthermore, considering thermal conductivity, cost, etc., aluminum foils such as A8079, A8021, A3003, etc. classified by JIS H4160, having a thickness of 50 to 200 μm are suitable, and in particular, a thickness of 70 to 150 μm. Those within the above range are preferable as the material of the metal foil layer (201).
The heat-fusible resin layer (202) constituting the inner surface of the container body (2B) (including the upper surface of the flange portion (23)) is made of, for example, a heat-fusible resin film. As the heat-fusible resin film, a general-purpose film such as a polypropylene resin film or a polyethylene resin film having a thickness of 10 to 200 μm, or a composite film thereof is used. It is preferable to be set to ˜100 μm.
The heat insulating resin layer (203) constituting the outer surface of the container main body (2B) can be formed of, for example, a heat resistant resin film bonded and laminated on the outer surface of the metal foil layer. Examples of heat-resistant resin films include polyethylene terephthalate resin films having a thickness of 12 to 50 μm, polyamide resin films, polybutylene naphthalate resin films, polypropylene resin films, polyethylene resin films, and composite materials thereof. Used.
The bonding between the metal foil layer (201) and the heat-fusible resin layer (202), and the bonding between the metal foil layer (201) and the heat-insulating resin layer (203) are performed via an adhesive layer (204), respectively. Done. For the adhesive layer (204), a two-component curable polyester-polyurethane resin-based adhesive or a polyether-polyurethane resin-based adhesive is used, and each thickness is about 1 to 15 μm. In view of improvement in properties and formability, the thickness is preferably 2 to 5 μm.

In the package (1B) according to the second embodiment, the lid (3B) is of an easy peel type that can be peeled off from the flange (23) of the container body (2B) and opened. .
Specifically, the cover material (3B) has a sealing material layer (302) formed of an easily openable resin film. As the easily openable resin film, a general-purpose film such as a polypropylene resin film or a polyethylene resin film having a thickness of about 10 to 200 μm or a composite film thereof is used. It is preferable to be about ˜100 μm.
Although not shown in the drawings, the lid (3B) has a knob portion that protrudes radially outward from a portion in the circumferential direction at its peripheral edge and is picked by a finger when the lid (3B) is peeled open. Is formed.
Further, in this embodiment, the outer resin layer (303B) of the lid member (3B) is formed by the surface coat layer. For example, the surface coat layer is formed by applying a coating agent obtained by dissolving or dispersing a coating resin, such as an epoxy resin, a nitrified cotton-based resin, an epoxy melamine resin, or a vinyl chloride-vinyl acetate copolymer resin, in a solvent. It is formed by applying and drying.

  In addition, about the layer structure and combination of a container main body and a cover material, it is not necessarily limited to the thing of the 1st and 2nd embodiment mentioned above, It can change suitably.

  Next, specific examples of the present invention will be described. However, the present invention is not limited to these examples.

<Lamination strength evaluation test for lid material>
A surface treatment layer made of a chemical conversion film is formed on one surface of an aluminum alloy foil of A8021 annealed according to JIS H4160 with a thickness of 20 μm by subjecting it to a chromate treatment, and two-component curing is performed on the surface of the surface treatment layer. A polyester-polyurethane resin adhesive of a mold is applied at an application amount of 3 g / m ² , an unstretched polypropylene resin film having a thickness of 30 μm is bonded, and a two-component curable polyester- By applying a polyurethane resin-based adhesive at an application amount of 3 g / m ² , attaching a polyethylene terephthalate resin film having a thickness of 9 μm, and allowing to stand for 3 days in a constant temperature bath at 40 ° C., and curing the adhesive, A composite sheet was prepared and used as a lid material for a hot beverage container of Example 1.

Chromate treatment is performed on one side of an A8021 annealed aluminum alloy foil classified in accordance with JIS H4160 with a thickness of 35 μm using a coating type treatment consisting of a mixture of phosphoric acid, chromium (III) salt, acrylic resin and water. Is applied to the surface of the base treatment layer, and a two-component curable polyester-polyurethane resin adhesive is applied at a coating amount of 3 g / m ² , and the thickness is 30 μm. A non-stretched polypropylene resin film is bonded together, and a surface coating agent made of an epoxy melamine resin is applied to the other surface of the aluminum alloy foil, dried and baked at 230 ° C., and kept in a constant temperature bath at 40 ° C. for 3 days. The composite sheet was produced by allowing to stand and curing the adhesive, and this was used as a lid for a hot beverage container of Example 2.

  A composite sheet was produced in the same manner as in Example 1 except that an aluminum alloy foil having no base treatment layer formed on both sides was used, and this was used as a lid for a hot beverage container of Comparative Example 1.

  A composite sheet was produced in the same manner as in Example 2 except that an aluminum alloy foil having no base treatment layer formed on both sides was used, and this was used as a lid for a hot beverage container in Comparative Example 2.

For each of the lid materials of Examples 1 and 2 and Comparative Examples 1 and 2, the laminate strength between the aluminum alloy foil layer and the unstretched polypropylene resin film layer was measured.
The laminate strength was measured by first cutting a sheet from a composite sheet into a strip shape having a width of 15 mm and a length of 100 mm, and preparing a sample in which an aluminum alloy foil layer and an unstretched polypropylene resin film layer were separated by 50 mm. Next, the aluminum alloy foil layer of the sample prepared above and non-stretched using a thermostat (TCR1W-200P manufactured by Shimadzu Corporation) tensile tester (Autograph MODEL AGS-X manufactured by Shimadzu Corporation) The ends of the polypropylene resin film layer were attached to upper and lower chucks in a thermostatic chamber of a tensile tester, and the laminate strength was measured at each ambient temperature of 25 ° C, 40 ° C, and 60 ° C. The results are shown in Table 1.

  As is clear from Table 1, in the case of the lid materials of Examples 1 and 2 in which the base treatment layer is formed on one side of the aluminum alloy foil, the comparison in which the base treatment layer is not formed at any atmospheric temperature Compared to the lid materials of Examples 1 and 2, the laminate strength was high.

<Presence or absence of delamination of cover material>
Next, the cup-shaped container main body (refer FIG. 1) vacuum-molded using polypropylene resin as a material was produced. The size of the container body was 65 mm in diameter (inner diameter) and 220 ml in capacity.
And each lid | cover material of the said Examples 1 and 2 and Comparative Examples 1 and 2 was heat-sealed to the flange part of the container main body filled with 160 ml of water, and 15 packaging bodies were produced for each lid | cover material. The heat-sealing was performed by heating the flange portion of the container body and the peripheral edge portion of the lid member stacked on the container body with a hot plate at 180 ° C. with a pressure of 90 kgf for 1 second. About 60 ml of head space was provided in the container body of each package.

The obtained package is housed in a commercially available showcase with a heating device (PET bottle warmer product number CD-P75 manufactured by Tanix Co., Ltd.), the heating device is set to 55 ° C., and the package is heated. Three packages using the lid were taken out every predetermined time, and the presence or absence of delamination of the lid was visually confirmed.
The results are as shown in Table 2 below. In Table 2, the denominator indicates the total number of samples, and the numerator indicates the number of samples in which delamination has occurred in the lid.

As is clear from Table 2, in the package using the lid material of Comparative Example 1, the lid material was obtained after 1 day, and in the package using the lid material of Comparative Example 2 after 3 days. Generation of delamination was observed between the aluminum alloy foil layer and the unstretched polypropylene resin film layer.
On the other hand, in the case of the packaging body using the lid materials of Examples 1 and 2, the occurrence of delamination in the lid material was not confirmed even after 4 days.

  The present invention can be suitably used as a package for selling beverages such as coffee, black tea, and Japanese tea in a heated state.

(1A) (1B): Package
(2A) (2B): Container body
(23): Flange
(3A) (3B): Cover material
(301): Metal foil layer
(302): Sealing material layer
(303): Outer resin layer
(304): Ground treatment layer
(C): Hot beverage

Claims (3)

A lid that is heat-sealed to the flange of the container body so as to cover the opening of the container body filled with hot beverage as a content, and is adhesively laminated to the metal foil layer and the inner surface of the metal foil layer It is provided with a sealing material layer and an outer resin layer laminated on the outer surface of the metal foil layer. A base treatment layer made of a chemical conversion film is previously formed on the inner surface of the metal foil layer, and the outer resin layer is heat resistant. A lid for a hot beverage container , comprising a stretched film and having an outer resin layer thickness of 0.5 to 38 μm .   The lid for a hot beverage container according to claim 1, wherein the chemical conversion film is formed by subjecting the surface of the metal foil to a chromate treatment or a non-chromium chemical conversion treatment using a zirconium compound. The lid for a hot beverage container according to claim 1 or 2 , wherein a lid is heat-sealed to the flange portion of the container body so as to cover the opening of the container body filled with hot beverage as a content. A package made of materials.

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