JP4511104B2 - Inorganic container lid and inorganic container using the same - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a lid for an inorganic container and an inorganic container using the same.
[0002]
[Prior art]
Conventionally, as a cover material for an inorganic container, a cover material obtained by laminating a thermal adhesive layer mainly composed of an ionomer or EVA (ethylene-vinyl acetate copolymer) on an aluminum foil has been widely used. However, for example, when a spice containing a large amount of a volatile component is filled and sealed with the lid, the lid is generated by the volatile component generated from the spice as a content during storage of the product. There was a risk that the adhesive strength of the material would be reduced and the sealed state would be impaired, and the quality of the contents could be hindered by the inflow of air and moisture. Also, when using a thermal adhesive layer with high thermal adhesive strength, such as a blended resin of modified ethylene acrylic acid copolymer and modified polypropylene, the lid cannot be opened with fingers during use, or the lid is in the process of being opened. It has been found that a failure to break occurs.
[0003]
[Problems of the Invention]
Then, even if it applies to the inorganic container filled with the foodstuff containing a volatile component that the subject of this invention solves the above-mentioned problem, adhesive strength falls during storage and a sealed state is impaired. The present invention also provides an inorganic container lid that can be easily opened with fingers during use, and an inorganic container using the same.
[0004]
[Means for solving problems]
In order to solve the above problems, in the present invention, a paper layer having a basis weight of 100 to 200 g / m ² , an adhesive layer, a metal thin film layer, an adhesive layer, and a glass transition temperature of −5 ° C. to −30 ° C. Polyester sealant films were sequentially laminated to form a food glass container containing volatile components or an easily openable lid for pottery . The lid and glass containers and pottery were sealed with the lid member is suitable especially for food comprising either or both of pinene or limonene as a volatile material.
[0005]
Embodiment
Embodiments of the present invention will be described below with reference to the accompanying drawings. As shown in FIG. 1, the lid 1 of an inorganic container is formed by laminating a metal thin film layer 4 on an outer paper layer 2 via an adhesive layer 3, and further interposing an adhesive layer 5 on the metal thin film layer 4. A polyester sealant film 6 is laminated.
[0006]
As the paper layer 2, paper having a basis weight of 100 to 200 g / m ² is suitable, and kraft paper, pure white roll paper, fine paper, imitation paper, western paper, Japanese paper, various coated papers and the like can be used. The paper layer 2 allows the lid material 1 to have an appropriate thickness, so that the lid material 1 can be easily pinched with fingers during use, and the lid material 1 can be easily opened without breaking during the opening. When the basis weight of these papers is less than 100 g / m ² , the thickness of the lid material 1 is thin and it is difficult to pinch it with fingers during use, and the lid material 1 is easily broken during opening. On the other hand, if the basis weight exceeds 200 g / m ² , it is inappropriate in terms of heat sealability, economy, and the like.
[0007]
The surface of the paper layer 2 can be printed or colored, and an OP varnish, an outer surface protective film, or the like can be further laminated. Of course, the back side (the metal thin film layer 4 side) of the paper layer 2 can be printed or colored, and the paper layer 2 can contain a moisturizing agent or the like as required.
[0008]
The adhesive layer 3 may be a dry laminate adhesive described later, but is preferably formed from one or more synthetic resin layers. The synthetic resin layer may be a coextruded film, a stretched film, an unstretched film, or the like. As the resin, polyethylene, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, ethylene-acrylic acid copolymer, ionomer, and the like can be used. Among these, polyethylene is preferable in terms of versatility and economy. A film in which aluminum, silica, alumina or the like is vapor-deposited at an arbitrary position can also be used. The thickness when the adhesive layer 3 is formed of a synthetic resin layer is not particularly limited, but is preferably about 9 to 40 μm. As a result, the lid member as a whole can be further thickened.
[0009]
For the metal thin film layer 4, an aluminum foil, an aluminum vapor deposition layer, or the like can be used for the purpose of improving the moisture resistance and light shielding property of the container. The material of aluminum is pure aluminum (JIS 1000 series, for example, 1N30, 1N70, etc.), Al-Mn series (3000 series, for example, 3003, 3004 etc.), Al-Mg series (same 5000 series), Al-Fe series (same as above). (8000 series (for example, 8021, 8079, etc.)) A material such as an aluminum alloy can be used, and the thickness is preferably 5 to 50 μm, more preferably 7 to 30 μm. The aluminum foil is preferably a semi-hard material or a soft material, and is preferably subjected to at least one heat treatment (usually 200 to 500 ° C.) after rolling. A hard material is not preferable as a packaging material from the viewpoint of increasing residual stress, flexibility and oil residue. When an aluminum foil is interposed, the moisture resistance and light shielding properties of the container are improved, and long-term storage at room temperature is possible. In place of the aluminum foil, a vapor deposition layer of aluminum may be interposed, but the thickness in that case is usually about 300 to 1200 angstroms.
[0010]
As the adhesive layer 5 used for bonding the metal thin film layer 4 and the polyester sealant film 6, it is preferable to use a polyether laminate or polyester dry laminate adhesive. When the dry laminate adhesive is used, the metal thin film layer 4 and the polyester sealant film 6 can be firmly bonded, and the occurrence of delamination can be suitably prevented when opening with fingers. The application amount of the dry laminate adhesive is about 0.5 to 10.0 g / m ² . If it is less than 0.5 g / m ² , the adhesive strength may be insufficient, and delamination tends to occur. On the other hand, even if it exceeds 10.0 g / m ² , no further improvement in adhesive strength is observed, which is undesirable in terms of moisture resistance and economy.
[0011]
Since the lid 1 of the present invention employs the polyester sealant film 6, even when applied to an inorganic container filled with a food containing a volatile component, the adhesive strength decreases during storage and the sealing performance is impaired. This can be prevented. The thickness of the polyester-based sealant film 6 is not particularly limited, but about 25 to 75 μm is appropriate from the viewpoint of adhesion with an inorganic container. The glass transition temperature of the polyester-based sealant film 6 is preferably about −5 ° C. to −30 ° C., and the polyester-based sealant film 6 having a glass transition temperature in this range has appropriate adhesiveness with an inorganic container and easy opening. It has been found to be particularly effective. By adopting such a polyester-based sealant film 6, it has been confirmed that it can be directly sealed (sealed) at the opening edge of an inorganic container such as glass, and an appropriate adhesion is maintained. The polyester contained in the polyester-based sealant film 6 may be modified, for example, as acid-modified. Examples thereof include acrylic acid, methacrylic acid, maleic acid, maleic anhydride, itaconic acid, and anhydrous. Examples thereof include those obtained by graft polymerization with an unsaturated carboxylic acid such as itaconic acid.
[0012]
Examples of the inorganic container used in the present invention include glass containers (bottles) and ceramics, and commercially available glass containers can also be used. The material of the glass is not particularly limited, and a known material such as soda lime glass, lead glass, borosilicate glass or the like can be selected. Further, the size of the container is appropriately selected depending on the internal volume. A flange may or may not be formed in the opening, and a coating layer such as a metal oxide may be applied to the opening. In addition, the thread part may be formed in the outer periphery of opening vicinity so that the screw cap provided with the opening and closing mechanism of a swing outlet can be attached.
[0013]
Examples of the food containing volatile components that are the contents of the inorganic container include foods containing a large amount of volatile components, such as spices, extracts thereof, fragrances, and alcohols. More specifically, examples of spices include pepper, yam, star anise, cloves, allspice, nutmeg and the like. Examples of alcohols include distilled liquors such as whiskey, brandy, vodka and tequila. Moreover, the lid | cover material and inorganic container of this invention can be effectively used especially with respect to the foodstuff containing volatile components, such as pinene and limonene.
[0014]
The structure of the lid 1 of the present invention is as described above, but in addition to this, an intermediate resin film, an outer surface protective film, an anchor coat layer, a printed layer, a colored layer, an overcoat layer, and adhesion other than those described above Laminating agent layers and the like is allowed. For the adhesion of each layer, a known method can be employed. For example, dry lamination, wet lamination, coextrusion using a two-component reactive polyester-based or two-component reactive polyester / polyurethane-based adhesive or the like. It can be laminated by methods such as extrusion lamination. Moreover, you may give uneven | corrugated type | molding (embossing) to the lid | cover material 1 of this invention using an uneven | corrugated type | molding (embossing) roll as needed. When the lid 1 and the inorganic container are sealed, they may be thermally bonded by heat sealing with a hot plate, high frequency sealing, ultrasonic sealing, or the like. When the lid 1 is sealed in an inorganic container and sealed, the sealing strength is about 8 to 25 N / 15 mm width when measured according to JIS Z1707.
[0015]
The shape and size of the lid material 1 of the present invention are arbitrary, but are, for example, substantially the same shape as the shape of the opening of the inorganic container and the same diameter as or slightly larger than the diameter of the opening. This is particularly effective in the case of a diameter that does not include a tab (knob portion) that partially protrudes at the periphery thereof. That is, the lid 1 according to the present invention can be peeled cleanly from the inorganic container without breaking even if it has such a shape and size. Moreover, when making the diameter of the lid | cover material 1 slightly larger than the diameter of the opening part of an inorganic container, it is preferable to make it about 0.5-3 mm larger than the diameter of the opening part of an inorganic container, for example. The lid 1 having such a shape and size is suitably applied to an inorganic container in which a screw portion is formed on the outer periphery in the vicinity of the opening as described above and a screw cap can be attached.
[0016]
【Example】
Paper having a basis weight of 120 g / m ² and one surface of an aluminum foil having a thickness of 20 μm were bonded to each other through a polyethylene resin (thickness after drying: 20 μm). Furthermore, the other surface of the aluminum foil and a polyester resin sealant film having a thickness of 50 μm and a glass transition temperature of −25 ° C. are bonded together with a polyurethane-based dry laminate adhesive (weight after drying: 3.5 g / m ² ) to produce a laminate. did. A circular lid of φ42 mm was punched out from this laminate, and high-frequency sealed at the opening (opening edge) of a cylindrical glass container of φ40 × height 85 mm filled with pepper.
[0017]
[Comparative Example 1]
A laminated body was produced in the same manner as in Example except that ionomer resin (thickness 50 μm) was used instead of the polyester resin sealant film. A circular lid member of φ42 mm was punched out from this laminate, and high-frequency sealed at the opening (opening edge) of a φ40 × 85 mm high glass container filled with pepper.
[0018]
[Comparative Example 2]
Instead of the polyester resin sealant film, a laminate was prepared in the same manner as in Example except that an ethylene-vinyl acetate copolymer (EVA) resin (thickness 50 μm) was used. A circular lid member of φ42 mm was punched out from this laminate, and high-frequency sealed at the opening (opening edge) of a φ40 × 85 mm high glass container filled with pepper.
[0019]
[Comparative Example 3]
Instead of the polyester resin sealant film, a laminate was produced in the same manner as in Example except that a blend resin (thickness 50 μm) of a modified ethylene acrylic acid copolymer and a modified polypropylene was used. A circular lid of φ42 mm was punched out from this laminate, and it was sealed with high-frequency sealing at the opening (opening edge) of a φ40 × 85 mm high glass container filled with pepper.
[0020]
Samples prepared in Examples and Comparative Examples were subjected to the following tests. The test results are shown in FIG.
[Seal strength]
Seal strength (N / 15 mm width) conformed to JIS Z 1707 7.5 heat seal strength. However, the sample was cut and removed at the opening edge of the opening of the glass container so that the cover material remained as a test piece having a width of 15 mm, and the maximum stress until the test piece peeled off from the opening edge was measured.
[Aging test]
After standing for 30 days in a 40 ° C. atmosphere, the seal strength was measured.
[Openability]
The periphery of the lid was pinched with the thumb and forefinger and pulled upward 90 degrees. In FIG. 2, ○ does not peel off only by lightly pulling, but when applied with moderate pressure, the lid material breaks off in the middle or part of the lid material does not remain on the opening edge of the container, and it peels cleanly △ indicates that the film was easily peeled by light pulling or had already been peeled off, and x indicates that it was not peeled even when pulled strongly.
[0021]
【effect】
1. Since a specific sealant film is used for the lid material of the present invention, it can be directly sealed at the opening edge of an inorganic container such as glass, and an appropriate adhesive force is maintained even after a aging test, so that it can be easily opened. Can be held.
2. Since the cover material of the present invention uses a relatively thick paper as the outer layer, it can be easily picked up with fingers during use and can be easily opened without breaking the cover material during the opening.
3. Since the lid material of the present invention does not contain harmful substances such as epoxy resin and vinyl chloride, or the like, it is preferable from the viewpoint of environment and health as a lid material for inorganic containers.
4). The inorganic container sealed with the lid material of the present invention maintains an appropriate adhesive force even after the aging test, and is substantially shielded from the outside air, thereby preventing the food that is the content from being spoiled or agglomerated. effective.
5). The inorganic container sealed with the lid material of the present invention can be stored for a long time in a stable state without easily detaching the lid material even if the contents contain volatile substances.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an example of a lid material of the present invention. FIG. 2 is a table showing test results of Examples and Comparative Examples.
1 Lid material 2 Paper layer 3 Adhesive layer 4 Metal thin film layer 5 Adhesive layer 6 Polyester sealant film

Claims (4)

It is a lid for a food storage container containing a volatile component and has a basis weight of 100 to 200 g / m ² of a paper layer, an adhesive layer, a metal thin film layer, an adhesive layer, and a glass transition temperature of −5 ° C. to −30. An easily openable lid for an inorganic container made of either a glass container or earthenware, characterized by sequentially laminating polyester sealant films at 0 ° C. The easy-open lid for an inorganic container according to claim 1, wherein the food contains either or both of pinene and limonene as a volatile component. Pottery sealed using peelable lid material according to claim 1 or 2. A glass container sealed with the easy-open lid according to claim 1.

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