JP5381295B2 - Inner seal material for sealing the mouth and a sealed container using the inner seal material - Google Patents

Description

The present invention relates to an inner seal material for sealing a container mouth and a container mouth sealed container using the inner seal. More specifically, the present invention relates to a container for food, medicine, cosmetics, etc., in particular, an inner seal material that is suitably used as a lid for a plastic container, and a sealed container that is hermetically sealed with the inner seal material.

In containers that contain instant coffee, creaming powder, dashi stock, health food, sprinkles, powdered cosmetics, toners and other foods, medicines, cosmetics, etc. In order to prevent deterioration due to contact with air or moisture, the container mouth is sealed with an inner seal material.

Such an inner seal material is generally formed by laminating a relatively thick reseal material mainly composed of paperboard and the like and a relatively thin seal material obtained by laminating a metal foil such as an aluminum foil and glassine paper so that a release layer can be formed. It is a general structure that consists of a laminated body.

When the cap is removed, the reseal material and the seal material are delaminated at the interface between them or in the release layer interposed between them, and the reseal material remains inside the cap, and the seal material is the container. The container mouth part is sealed as a sealing lid member that remains in the state of being attached to the mouth part.

Prior to use, some or all of the lid material (seal material) is peeled off and removed by the user, but the reseal material remains inside the cap even after the lid material is removed. By mounting, the reseal material closes the container mouth and can exhibit a certain quality-preventing effect.

In order to enhance the storage effect of the contents, a desiccant is loaded inside the cap to absorb moisture in the container.
As the desiccant to be loaded, a tablet-shaped desiccant molded body is generally used with an inorganic compound having a drying function together with various inorganic binders. However, these molded bodies are often destroyed by a slight stress or vibration, and in the worst case, there is a possibility that a problem of foreign matter mixing into the contents may occur.

In order to avoid the problem, a type in which this tablet-shaped desiccant molded body is packaged with thin paper has been seen, but in this case, the thin paper that wraps the tablet-shaped desiccant molded body is It has become a problem to adversely affect the removal of moisture in the container.
In order to solve the above problems, a desiccant layer formed by laminating a resin kneaded with a desiccant has the same diameter as the diameter of the mouth of the container, and is disposed on the lower surface of the sealing material. A combined inner seal material has been proposed (see Patent Document 1).
In addition, an inner seal material has been proposed in which a desiccant layer formed by laminating a resin kneaded with a desiccant is disposed on the reseal material side (see Patent Document 2).
However, even if the desiccant layer is provided on the sealing material, moisture absorption before opening is possible, but when the sealing material is peeled off and opened, the sealing material may be removed from the container mouth. In addition, the water absorption function after opening has been lowered, and there has been a risk of hindering the storage of the contents.
On the other hand, the configuration in which the desiccant layer is provided on the reseal material is in a state in which the mouth portion is hermetically sealed and the contents can be stored by the moisture-proof material layer of the seal material. The water absorption function could not be demonstrated.

JP 2002-186657 A Japanese Utility Model Publication No. 60-163256

The present invention ameliorates the above problems, and has a function of absorbing moisture that has permeated into the container body or moisture originally remaining in the head space, and also has a constant moisture absorption function even after opening. An object is to provide an inner seal material for sealing a mouth portion.
It is another object of the present invention to provide a sealed container using the inner seal material and sealing the mouth of the container body.

The invention according to claim 1 comprises a sealing material having at least a moisture-proof material layer and a moisture-absorbing functional layer, and a resealing material having at least an elastic sheet layer, a moisture-proof material layer, and a moisture-absorbing functional layer, and the sealing material In the inner sealing material for sealing the container mouth portion, the sealing material and the resealing material are each provided with the moisture absorption function layer on the container side of the moisture-proof material layer. Is an inner seal material for sealing a container mouth.

The invention according to claim 2 is an inner seal material for sealing a container mouth, wherein the surface of the seal material and the back surface of the reseal material are laminated via a release layer.

According to a third aspect of the present invention, there is provided an inner seal material for sealing a container mouth, wherein the moisture absorption functional layer provided on the sealing material and the reseal material is a moisture absorption functional layer of a different moisture absorption type.

The invention according to claim 4 is an inner seal material for sealing a container mouth, wherein one of the moisture absorption functional layers is a humidity control type.

The invention according to claim 5 is an inner seal material for sealing a container mouth, wherein one of the moisture absorption functional layers is an absolutely dry type.

The invention according to claim 6 is an inner seal material for sealing a container mouth, wherein the moisture-proof material layer includes an aluminum foil.

The invention according to claim 7 is an inner seal material for sealing a container mouth, wherein the seal material has a notch for opening.

The invention according to claim 8 is a sealed container characterized in that the mouth of the container body is sealed by the inner seal material for sealing a container mouth described in any one of the above.

The invention according to claim 9 is a sealed container characterized in that the container body is a plastic container.

According to the invention of claim 1 of the present invention, since both the resealing material to be separated and the sealing material are provided with the moisture absorption function layer, the contents remain in the container body from the start of storage to the start of use. It is possible to reliably absorb the moisture that enters and the moisture that enters from the side wall of the container body.
In addition, even after the sealing material separated on the container body side is peeled off, the resealing material separated into caps has a moisture absorption function layer, so that the humidity inside the container can be controlled to be dry or constant even after opening. It is.
Therefore, it is possible to provide a sealed container that does not cause quality deterioration of contents due to moisture.

According to the invention of claim 2, when the inner sealing material for sealing the container mouth portion is opened, the resealing material and the sealing material to be separated are integrated, and the cap is rotated to open the sealing material on the container body side. Since the reseal material is separated on the cap side, even if the cap is removed, the contents are protected, and it is found that the container has been opened. Therefore, it is possible to provide a sealed container that can be checked for tampering prevention.
In addition, since both have a moisture absorption functional layer, it is possible to control the humidity in the container to a dry state or a constant humidity even after opening.

According to the invention of claim 3, the moisture absorption functional layer corresponding to the atmosphere inside the container body before opening and the atmosphere inside the container body after opening can be arranged, and the contents can be stored more effectively. is there.
According to a fourth aspect of the present invention, when the moisture absorption recording layer is of a humidity control type, the humidity in the container body can be maintained within a certain range and stored in an atmosphere that matches the contents. be able to.
In addition, according to the invention of claim 5, by making the moisture absorption recording functional layer an absolute dry type, the humidity in the container body can be reduced as much as possible, and the contents are stored in a dry state. Can do.

It is sectional drawing which shows one Example of the inner seal material of this invention. It is sectional drawing which shows the other example of the inner seal material of this invention. It is sectional drawing which shows the other example of the inner seal material of this invention. It is sectional drawing which shows the other example of the inner seal material of this invention. It is sectional explanatory drawing which shows the state which loaded the inner seal material in the cap and sealed the opening part of the container main body. FIG. 6 is an explanatory cross-sectional view showing a state where the cap of the container shown in FIG. 5 is opened.

As shown in FIG. 1, the inner seal material 1 for sealing a container mouth of the present invention has an adhesive layer 101, a moisture absorption functional layer 102, a moisture-proof material layer 103, an adhesive layer 105, a printing layer 106, and a printing from the lower surface side. A sealing material 2 in which a base material layer 107 is laminated, and a resealing material 3 in which a moisture absorption functional layer 202, a moisture-proof material layer 203, and an elastic sheet layer 205 are laminated, and the surface of the printing base material layer 107 of the sealing material 2, It is an inner seal material for sealing a mouth portion in which the moisture absorption functional layer 202 of the reseal material 3 is overlapped and adhered.

2 shows, from the lower surface side, a sealing material 2 in which an adhesive layer 101, a moisture absorption functional layer 102, a moisture-proof material layer 103, an adhesive layer 105, a printing layer 106, and a printing substrate layer 107 are laminated, a peeling layer 208, moisture It is composed of the resealing material 3 in which an absorption functional layer 202, a moisture-proof material layer 203, and an elastic sheet layer 205 are laminated. It is an inner seal material for sealing the mouth part integrated with each other.
Here, the peeling layer 208 is not provided in the central portion but is provided in the peripheral portion. Therefore, the adhesive layer 300 is in a state of being bonded to the moisture absorption functional layer 202 at the central portion.
Further, the sealing material 2 has a notch 303 that reaches the printing substrate layer 103 from the lower surface side at the position of the central portion where the release layer 208 is not provided, with the same diameter as the central portion or a slightly larger diameter. Is provided.

FIG. 3 is a cross-sectional view showing another inner seal material 1.
From the lower surface side, the sealing material 2 in which the adhesive layer 101, the moisture absorption function layer 102, the moisture-proof material layer 103, and the release layer 108 are laminated, the printing base material layer 207, the printing layer 206, the moisture absorption function layer 202, and the moisture-proof material. The adhesive layer 300 is formed of the reseal material 3 in which the layer 203 and the elastic sheet layer 205 are laminated, and the release layer 108 surface of the seal material 2 and the print base material layer 207 surface of the reseal material 3 are partially provided with an adhesive. It is an inner seal material for sealing the mouth part integrated with each other.
In the case of the above configuration, the printing base material layer 207 is preferably made of a material having air permeability, for example, a porous material.

FIG. 4 is a cross-sectional view showing another inner seal material 1.
From the lower surface side, the sealing material 2 in which the adhesive layer 101, the moisture absorption functional layer 102, the moisture-proof material layer 103, the adhesive layer 105, the printing layer 106, and the printing base material layer 107 are laminated, the release layer 208, and the moisture absorption functional layer 202. , Comprising a reseal material 3 in which a moisture proof material layer 203 and an elastic sheet layer 205 are laminated, and the adhesive is partially provided on the surface of the printing base material layer 107 of the seal material 2 and the surface of the release layer 208 of the reseal material 3. In addition, the inner seal material for sealing the mouth is integrated through the adhesive layer 300.

Then, as shown in FIG. 5, the inner seal material 1 shown in FIG. 2 is loaded into the cap 5 with the reseal material 3 side as the cap side and capped with the container body 4, and then the mouth of the container body 2. In addition, the inner seal material is in close contact, and the mouth of the container body 4 is sealed.

FIG. 6 shows the separation part surrounded by the notch 303 of the sealing material 2 while peeling off from the interface between the peeling layer 208 and the adhesive layer 300 by rotating the cap 5 of the sealed container in the state shown in FIG. When 304 is separated together with the reseal material 3, it is removed to the cap 5 side.
Moreover, although not shown in figure, it is good also as a structure where the peeling layer itself isolate | separates within a layer by rotating the cap 5 of a sealed container.

As described above, when the inner cap material having the configuration shown in FIG. 5 is used, at the same time that the cap is removed, the separation portion 304 surrounded by the cut portion 303 of the sealing material 1 is bonded and separated to the resealing material side. , And an extraction port 308 is formed.

Among the configurations of the inner seal material 1, the moisture absorption functional layers 102 and 202 may include a configuration in which protective layers are provided on both sides of a resin layer containing an inorganic compound having hygroscopic performance.
The inorganic compound used for the resin layer containing the inorganic compound having moisture absorption performance used for the moisture absorption functional layers 102 and 202 is an absolutely dry type in which the humidity in the bottle is kept dry (relative humidity of 10% or less), or The components differ depending on the humidity control type in which the environment is adjusted to a constant humidity (relative humidity 20 to 70%).

In the former case, a desiccant that does not absorb or desorb moisture adsorbed by the desiccant or is difficult to absorb or desorb is used.
Examples of the desiccant include calcium oxide, zeolite, and silica gel.

In the latter case, a desiccant that can absorb and desorb moisture is preferable in order to keep the moisture (vapor pressure) in the packaging container and the moisture (vapor pressure) absorbed by the desiccant.
The desiccant is preferably selected from at least one of sulfate compounds such as magnesium sulfate and baked baked alum, activated alumina, activated carbon, and clay mineral.

By blending a desiccant composed of an inorganic compound having hygroscopic performance into various thermoplastic resins, the moisture absorbing layer 302 using a resin having moisture absorbing ability can be obtained.
Examples of the thermoplastic resin blended with the desiccant include α-olefins (butene-1, hexene-1, octene-1, etc.) using a multisite catalyst such as low density polyethylene, medium density polyethylene, high density polyethylene, and Ziegler-Natta catalyst. 4-methylpentene-1, etc.)-Alpha olefin copolymers such as polypropylene, polybutene-1, polyalphaolefins such as poly-4-methylpentene-1, random polypropylene, block polypropylene, etc. Coalescence can be used.
Resins obtained by copolymerization of two or more α-olefins such as ethylene-propylene-butene copolymer, butene-propylene copolymer, and propylene-butene-hexene copolymer can also be used.
A polyolefin resin such as an ethylene-cyclic olefin copolymer can also be used.
Further, esterified products of ethylene-α, β-unsaturated carboxylic acid, especially ethylene-methyl (meth) acrylate, ethylene-ethyl (meth) acrylate, ethylene- (meth) acrylate n-butyl, ethylene- (meth) I-butyl acrylate, t-butyl ethylene- (meth) acrylate, and the like can also be used.

Next, as a method for producing a resin layer in which an inorganic compound having hygroscopic performance is blended, a material prepared by adjusting the inorganic compound having hygroscopic performance according to the purpose to 1 to 50 wt% and thermoplastic resin to 50 to 99 wt% Are dry blended using a ribbon mixer, a tumbler mixer, a Henschel mixer or the like.
Next, using a kneader such as a single screw extruder or twin screw extruder or a Banbury, for example, kneading at a melting point of 280 ° C. or less, preferably 260 ° C. or less, more preferably 240 ° C. or less. It is obtained by.
In that case, you may surface-treat various functional phases with dispersing agents, such as an olefin type wax, as needed. The obtained strand is cooled by air cooling or water cooling, and after pelletizing, it is stored in a packaging form such as an aluminum bag.
And it can manufacture by film-forming by a T-die method, an inflation method, etc.

However, a resin layer alone containing an inorganic compound having hygroscopic performance is likely to be quickly absorbed and saturated when a packaging material is produced. Therefore, it is composed of a thermoplastic resin layer on at least one side, preferably on both sides. It is preferable to provide a protective layer.
The material of the protective layer is preferably selected from various thermoplastic resins that contain the above-described inorganic compound having hygroscopic performance.
In this case, the resin layer 302 and the protective layer 301 containing an inorganic compound having hygroscopic performance can be formed by a technique such as a T-die method or an inflation method by coextrusion.

Examples of the moisture-proof material layer 103 include an aluminum foil, a metal vapor-deposited film, and an inorganic oxide vapor-deposited film, and an aluminum foil having a thickness of 5 to 30 μm is most preferable from the viewpoint of moisture-proof and the thickness to be used.
The moisture-proof material layer 103 can be laminated on the opposite side of the moisture absorption functional layer 104 from the container body to prevent moisture from being transmitted from the outside.

The printing substrate layer 207 may be a paper substrate such as single-side coated paper or glassine paper, or a plastic substrate such as polyethylene terephthalate (PET) or stretched polypropylene (OPP).
Further, the printing substrate layer 207 may be used as the moisture-proof material layer by using a material having excellent moisture resistance or a composite material.
Specifically, a composite material in which an aluminum foil is laminated on a plastic substrate such as polyethylene terephthalate (PET) or expanded polypropylene (OPP), or a material used for the moisture-proof material layer may be used as the printing substrate layer.

The peeling layers 108 and 208 are layers that peel due to the turning force when the cap is opened, and the material of the peeling layers 108 and 208 may be selected from materials whose adhesion strength is weaker than the adhesion strength between other layers.
For example, polyolefins such as polyethylene and polypropylene, chlorinated rubber, nitrile cellulose, polyamide, chlorinated polyolefin, urethane, acrylic cellulose, ethylene vinyl alcohol, vinyl acetate, vinyl acetate, chlorinated polyolefin, chlorinated polypropylene, cellulose acetate, maleic acid At least one resin such as melamine and alkyd, or a resin selected from waxes or resins containing waxes can be used.

The adhesive layer 300 is not coated on the entire surface, but in the form of dots (dots), dotted lines, etc. in order to maintain the interlayer strength when creating the inner seal material and to be able to be peeled off by the turning force when the cap is opened. By applying in the pattern, it is easy to peel off by adhering in the form of dots or lines in the entire surface where the adhesive layer and the release layer are in contact.
The adhesive layer 300 includes, for example, polyolefins such as polyethylene and polypropylene, chlorinated rubber, nitrile cellulose, polyamide, chlorinated polyolefin, urethane, acrylic cellulose, ethylene vinyl alcohol, vinyl chloride vinyl acetate, vinyl acetate, chlorinated polyolefin, and chlorinated polypropylene. , At least one resin such as cellulose acetate, maleic acid, melamine, and alkyd. A hot melt obtained by mixing a resin such as ethylene vinyl alcohol or ethylene acrylate with a wax such as paraffin or a tackifier such as rosin can also be used.

The release layer may be an easy-peeling polyolefin layer having a polymer alloy layer mixed with at least a polyolefin-based elastomer instead of the release varnish.

The elastic sheet layer 205 has a sealing function as a packing function, and specifically, an eight-way sheet such as a paperboard, a foamed polyethylene sheet, and a foamed polypropylene sheet, or a combination of these can be used. At this time, the elastic sheet layer preferably has a thickness of 100 μm to 2000 μm.

<Example 1>
From the cap side
An elastic sheet layer (foamed polyethylene 500 μm) and a moisture absorption functional layer having the following constitution were laminated via a melt-extruded low-density polyethylene layer (LDPE 20 μm) to form a reseal material.
On the other hand, a release layer made of a mixed resin of nitrocellulose / polyamide = 50/50 is provided on the opposite side of the printing layer film (OPP 20 μm) made of stretched polypropylene provided with a printing layer on one side, while the printing A soft aluminum foil (9 μm), a moisture-absorbing functional layer having the following constitution, and a low-density polyethylene (20 μm) were laminated on the layer side through a melt-extruded low-density polyethylene layer (LDPE 20 μm) to obtain a sealing material.
Then, the moisture absorption functional layer surface of the reseal layer and the release layer surface of the seal layer were integrated by an adhesive layer in which an adhesive varnish was partially provided from a vinyl acetate resin to obtain an inner seal material.
(Moisture absorption functional layer:
Inflation film formed of LDPE (20 μm) / LDPE (A) + calcium oxide (B) (30 μm) / LDPE (20 μm) With respect to 50 wt% LDPE (A) resin, calcium oxide (B) having a particle size of 5 μm was added. 50wt%)

<Example 2>
A dry type inner seal material was obtained in the same manner as in Example 1 except that synthetic zeolite having a particle size of 5 μm was used instead of calcium oxide having moisture absorption performance used in the moisture absorption function layer of Example 1.

<Example 3>
The same procedure as in Example 1 was performed except that a calcium oxide having a particle size of 5 μm was used in place of the calcium oxide having moisture absorption performance used in the moisture absorption function layer of the sealing material of Example 1, and the humidity was adjusted to about 50% relative humidity. A type of inner seal material was obtained.

<Example 4>
The inner layer of the humidity control type was carried out in the same manner as in Example 1 except that a baked potato with a particle size of 5 μm was used instead of the calcium oxide having moisture absorption performance used in the moisture absorption function layer of Example 1. A sealing material was obtained.

<Example 5>
A dry-type inner seal material was obtained in the same manner as in Example 1 except that PET (12 μm) / silicon oxide deposited film (10 nm) was used instead of the soft aluminum foil as the moisture-proof material layer.

<Example 6>
A dry type inner seal material was obtained in the same manner as in Example 1 except that 2 μm of a vinyl chloride resin heat seal varnish was applied as an adhesive layer to be adhered to the container body.

<Example 7>
From the cap side, an elastic sheet layer (foamed polyethylene 500 μm) and a moisture absorption functional layer having the following constitution were laminated via a melt-extruded low-density polyethylene layer (LDPE 20 μm) to obtain a reseal material.
On the other hand, a printing base film (OPP20 μm) made of stretched polypropylene provided with a printing layer on one side, a soft extruded aluminum foil (9 μm) through the melt-extruded low density polyethylene layer (LDPE 20 μm) on the printing layer side, A moisture absorption functional layer having a structure and low density polyethylene (20 μm) were laminated to obtain a sealing material.
The reseal layer and the seal layer were overlapped and adhered to form an inner seal material.

<Comparative Example 1>
An inner seal material was obtained in the same manner as in Example 1 except that calcium oxide having hygroscopicity used in the moisture absorption function layer was not blended and all was LDPE.

<Creation of evaluation sample>
Regarding the capability confirmation of the resin composition of the present invention,
Container body bottle: By injection molding, the outermost layer is made of high-density polyethylene (0.6 mm) and the innermost layer is made of low-density polyethylene (1.0 mm). The volume is 60 mm in height, bottom area, and opening area is 1250 mm ² . (75000 mm ³ ) was formed into a cylindrical container.
The basis weight of the resin composition layer of this container was about 20 g, and the thickness was 1.5 mm.
The mouth portion has a structure in which screw screws are formed.
The inner seal material was extracted in accordance with the shape of the opening to have an area of 1250 mm ² .

<Evaluation method>
After the inner seal material is loaded into the cap and the humidity sensor is placed inside the bottle, the cap is capped into the bottle. Examples 1-4 and Examples 6 and 7 perform IH sealing with an electromagnetic induction superheater, Moreover, Example 5 obtained the sealed container which adhered and sealed the inner seal material to the opening part by the heat seal method.
This sealed container was stored in a constant temperature and humidity chamber at 40 ° C. and 90% RH for 3 months, and a change in humidity inside the sealed container was measured over time.
The results are shown in Table 1.

DESCRIPTION OF SYMBOLS 1 ... Inner seal material 2 ... Seal material 3 ... Reseal material 4 ... Container main body 5 ... Cap 101, 105, 300 ... Adhesive layer 102, 202 ... Moisture absorption functional layer 103, 203 ... moisture proof material layer 205 ... elastic sheet layer 108, 208 ... release layer 301 ... protective layer 302 ... moisture absorption layer 303 ... cut 304 ... separation part 308 ... Extraction port

Claims (9)

A seal material having at least a moisture-proof material layer and a moisture-absorbing functional layer, and a reseal material having at least an elastic sheet layer, a moisture-proof material layer, and a moisture-absorbing functional layer, and the surface of the seal material and the back surface of the reseal material are An inner seal material for sealing a container mouth portion, wherein the seal material and the reseal material each include the moisture absorption function layer on the container side of the moisture-proof material layer. Inner seal material. The inner sealing material for sealing a container mouth according to claim 1, wherein the surface of the sealing material and the back surface of the resealing material are laminated via a release layer. 3. The inner seal material for sealing a container mouth according to claim 1, wherein the moisture absorption functional layers provided on the sealing material and the reseal material are moisture absorption functional layers of different moisture absorption types. 4. The inner sealing material for sealing a container mouth according to claim 1, wherein one of the moisture absorption functional layers is a humidity control type. 5. 4. The inner sealing material for sealing a container mouth according to claim 1, wherein one of the moisture absorption functional layers is an absolutely dry type. 6. The inner seal material for sealing a container mouth according to claim 1, wherein the moisture-proof material layer includes an aluminum foil. The inner seal material for sealing a container mouth according to any one of claims 1 to 6, wherein the seal material has a notch for opening. A sealed container, wherein the mouth of the container body is sealed with the inner seal material for sealing a container mouth according to claim 1. The sealed container according to claim 8, wherein the container body is a plastic container.

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