JP3707112B2 - Paper container with peel-type cap - Google Patents

Description

[0001]
FIELD OF THE INVENTION
The present invention relates to a paper container that is provided with a peel-type stopper and has a low adsorptivity to contents. The innermost surface of the paper container of the present invention is coated with low-adsorbing polyethylene terephthalate, and the peel-type plug portion reliably seals the opening.
[0002]
[Prior art]
Conventionally, various liquid beverages such as sake, juice, milk, and lactic acid beverages are commercially available by filling paper containers. FIG. 1 is a perspective view of a conventional paper container provided with a peel-type stopper, and FIG. 2 is a schematic sectional view showing the stopper part 2 of FIG. As shown in FIG. 2, in such a container 1, in the stopper portion 2, the outside of the opening 11 provided in the paper container body 10 in which the front and back of the cardboard 12 are covered with the outer surface layer 13 and the inner surface layer 14, and From the inside, the front window material 20 and the back window material 30 are bonded together by heat sealing so as to sandwich the container body 10.
[0003]
As the outer surface layer 13 of the container body 10, polyethylene (LDPE) is usually used to ensure printing characteristics, and the inner surface layer 14 is similarly coated with polyethylene. Further, the back window member 30 is a polyethylene film, and the front window member 20 is a polyethylene film on the back layer 23 on the inner surface side of the intermediate layer 21 made of aluminum foil, and the biaxially stretched polyethylene terephthalate ( A laminate seal provided with a PET) film is usually used.
[0004]
2, the front window material 20 is pseudo-adhered to the outer surface layer 13 applied with the peeling varnish on the outer surface of the container body 10, and the back window material 30 is attached to the inner surface layer 14 of the container body 10. As well as being fused, the back window layer 23 made of polyethylene and the back window material 30 (polyethylene) of the front window material 20 are heat-sealed to ensure high sealing performance.
[0005]
OBJECT AND DISCLOSURE OF THE INVENTION
However, in recent years, as the demands on the quality of foods and beverages have become stricter, it has been studied to cover the inner surface of a paper container main body with a polyester resin having a lower adsorptivity and a higher aroma retention. In such a plug portion of a paper container, the plug portion cannot be completely sealed using the conventional back window material and front window material.
[0006]
The present invention is intended to provide a peel-type plug portion of a paper container using a polyester resin having a low adsorptivity to contents and a high perfume retention property as an inner surface layer. In conventional paper containers with peel-type stoppers, the inner surface layer of the container body is polyethylene and has high adsorptivity to the contents, and the polyethylene component of low molecular weight is eluted into the contents and the polyethylene odor is transferred to the contents. There is a problem.
[0007]
The present invention relates to a paper container having an opening and an outermost layer made of polyethylene and an innermost layer made of a polyester resin. A paper container provided with a peel-type plug that is bonded to the back surface of the peripheral edge of the opening and to which front and back window materials are bonded, wherein at least the outermost layer of the back window material is made of a polyester resin, The present invention provides a paper container provided with a peel-type stopper whose innermost layer is a polymer alloy containing a polyester resin and a modified polyethylene.
[0008]
In the paper container of the present invention, a (homo) polyester resin that has excellent fragrance retention and low adsorptivity is used for the inner surface layer that is a sealant inside the container body. For this reason, at least the outermost layer of the back window material (the portion in contact with the inner surface layer of the container body) is made of polyester resin so that it can be adhered to the container body, while at least the innermost surface of the front window material (the portion in contact with the outer surface layer of the container body) In this case, a polymer alloy of PET and polyethylene is used so as to adhere to the back window material and to allow pseudo-adhesion to the surface layer of the container body.
[0009]
[Preferred specific example]
Next, the present invention will be described in more detail based on specific examples with reference to the drawings. FIG. 3 is a development view of the paper container of the present invention, and FIG. 4 is a schematic cross-sectional view showing the mouth plug portion. As shown in FIG. 3, in the present invention, the developed view of the container body 10 is the same as the developed view of a rectangular paper container of a known form. As shown in FIG. 4, the container body 10 has an outer surface layer 13 made of polyethylene on the outer surface side of the cardboard 12 as a core material, and an inner surface layer 14 made of polyester resin on the inner surface side. An opening 11 serving as a spout is provided. The front window material 20 and the back window material 30 are pasted and fixed to the opening 11 by a heater set at an appropriate temperature from the outside and the inside. By this fusion or adhesion, the front window material 20 is pseudo-adhered to the outer surface layer 13 of the container body 10, while the back window material 30 is completely adhered to the inner surface layer 14 of the container body 10. In general, fusion (thermal bonding) is preferable as the bonding means.
[0010]
The front window member 20 has an intermediate layer 21 made of an aluminum foil, and a surface layer 22 made of a biaxially stretched polyethylene terephthalate film is laminated on the outer surface side thereof, while the inner surface side in contact with the outer surface layer 13 of the container main body 10. A polymer alloy made of a mixture of a polyester resin and a modified polyethylene such as an ionomer resin is laminated on the back surface layer 23. In addition, the polyester resin content in the polymer alloy is set in consideration of peelability. Examples of such commercially available polymer alloys suitable for the back layer 23 include Sealer PT (manufactured by Mitsui DuPont Polychemical Co., Ltd.).
[0011]
On the other hand, the back window material 30 is completely adhered to the inner surface layer 14 of the container body 10 and is completely adhered to the back surface layer 23 of the front window material 20. The back window member 30 is preferably an amorphous polyester resin that can be heat sealed at about 150 ° C. or less. The polyester resin used for the front window material and the back window material can be obtained through a polycondensation reaction after direct esterification of an acid component and an alcohol component by a conventional method, or after a transesterification reaction. Examples of the acid component include aromatic carboxylic acids such as terephthalic acid, phthalic acid, isophthalic acid, and naphthalenedicarboxylic acid, and aliphatic carboxylic acids such as succinic acid, glutaric acid, adipic acid, and sebacic acid. Examples of the alcohol component include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, diethylene glycol, neopentyl. Examples include diols such as glycol, polyethylene glycol, and cyclohexanedimethanol.
[0012]
In addition, as a layer structure of the container main body, according to the contents and purpose as in the case of conventionally known containers such as polyethylene, aluminum foil, stretched PET layer and the like between the cardboard 12 and the inner surface layer 14 or the outer surface layer 13. An appropriate layer may be provided. Further, a peeling varnish may be provided on the outer surface layer 13 in the same manner as in the past to realize pseudo adhesion with the front window material 20.
[0013]
【The invention's effect】
The paper container having the peel-type stopper of the present invention has a high scent retention property and a low adsorptivity. The stopper of the container of the present invention has sufficient strength, does not leak, and can withstand contents protection and long-term storage.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a conventional container.
FIG. 2 is a schematic cross-sectional view showing the plug portion of FIG.
FIG. 3 is a development view of a specific example of the container of the present invention.
FIG. 4 is a schematic cross-sectional view of a cap portion of the container of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Container main body 2 Cap part 10 Container main body 11 Opening part 12 Cardboard 13 Outer surface layer 14 Inner surface layer 20 Front window material 21 Intermediate layer 22 Surface layer 23 Back surface layer 30 Back window material

Claims (1)

  For a paper container having an opening, the outermost layer being polyethylene and the innermost layer being made of polyester resin, the front window material is pseudo-bonded to the peripheral surface of the opening of the paper container, and the back window material is the peripheral edge of the opening of the paper container A paper container with a peel-type plug that is bonded to the back surface and to which the front and back window materials are bonded. At least the outermost layer of the back window material is made of polyester resin, and at least the innermost layer of the front window material is polyester. A paper container provided with a peel-type stopper which is a polymer alloy containing a resin and modified polyethylene.

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