JP6160047B2 - Paper cup - Google Patents

Description

  The present invention relates to a paper cup for storing instant foods and the like, and more particularly, to a paper cup for foods and beverages such as instant noodles and soups, which are filled and sealed with contents during distribution and used by pouring hot water during eating.

  Conventionally, as a paper cup having a heat insulation property, for example, Patent Document 1 describes a paper cup in which a side wall of a cup body is covered and adhered with a heat insulation protective cover.

  However, in the paper cup having the above heat insulating property, the laminated body made of the low-density polyethylene layer structure as the sealant layer on the inner surface of the paper base material is used for the cup body, so that the moisture resistance is inferior, and therefore the filled dry state. There was a problem that the contents of the product absorbed moisture during distribution, and the taste was deteriorated.

  In addition, instant foods may be stored and sold near pharmaceuticals in drug stores and other stores where pharmaceuticals are handled, and there is a problem of incense that causes the scent of pharmaceuticals to move to instant foods.

  As an improvement of the above problems, for example, Patent Document 2 describes a paper cup in which a barrier film obtained by depositing a metal foil, a metal or an inorganic oxide on a plastic film is laminated between a paper layer and a sealant layer. Has been.

  However, this paper cup has a problem that the layer becomes thick or the plastic film becomes stiff, so that the moldability is lowered and the mold needs to be adjusted or corrected. Further, not only the moldability but also the blank serving as the body of the paper cup has a problem that the curl is generated due to the influence of the heat of the extruded resin used when being bonded to the film. Further, in the process of punching into a blank shape, since the film is in the intermediate layer, the film residue (beard) remains on the end face, and there is a risk of contamination.

JP-A-8-58762 JP 2003-146321 A

  The present invention has been made in view of the above-described conventional problems, and has reduced moldability due to the use of the barrier film and prevents generation of curls and whiskers, and has moisture resistance and aroma retention. It is an object to provide a paper cup.

In order to solve the above problems, a paper cup according to the present invention is:
A paper cup having a paper side wall and a bottom wall provided with a paper layer and an inner sealant layer, and having an outward curl portion formed on an upper edge of the side wall,
Between the front SL paper layer and the sealant layer, in which is formed of a laminated body having only the resin layer comprising a cyclic polyolefin laminated on the paper layer through the adhesive polyimide.

  With the above-described configuration, the paper cup can have excellent moisture resistance and aroma retention. For this reason, there is little deterioration of the content in storage and it can be stored for a long period of time. In addition, the use of a barrier film in which a metal foil, a metal or an inorganic oxide is vapor-deposited on a plastic film can be used to prevent deterioration of moldability, curl and whisker generation, and to make a layer containing a cyclic polyolefin thin. it can. Here, the aroma retaining property refers to the property of preventing the scent from the outside from being transferred to the contained item and keeping the scent of the contained item itself.

  The cyclic polyolefin is preferably selected from the group consisting of a ring-opening metathesis polymer obtained by polymerizing a cyclic olefin by a metathesis ring-opening polymerization reaction, and a copolymer of a cyclic olefin and an α-olefin.

The cyclic olefin is
Bicyclo [2.2.1] hept-2-ene,
Tricyclo [4.3.0.1 ^2.5 ] -3-decene,
Tricyclo [4.4.0.1 ^2.5 ] -3-undecene,
Tetracyclo [4.4.0.1 ^2.5 1 ^7.10 ] -3-dodecene,
Pentacyclo [6.5.1.1 ^3.6 . 0 ^2.7 . 0 ^9.13 ] -4-pentadecene,
Pentacyclo [7.4.0.1 ^2.5 . 1 ^9.12 . 0 ^8.13 ] -3-pentadecene,
Pentacyclo [6.5.1.1 ^3.6 . 0 ^2.7 . 0 ^9.13 ] -4,10-pentadecadien,
Pentacyclo [8.4.0.1 ^2.5 . 1 ^9.12 . 0 ^8.13 ] -3-hexadecene, and preferably selected from the group consisting of these derivatives.

  The thickness of the layer containing the cyclic polyolefin is preferably 10 μm to 30 μm.

  A paper cup having excellent moisture resistance and aroma retention by forming a paper cup in which at least the side wall of the paper container is a laminate in which a layer containing a cyclic polyolefin is laminated between a paper layer and a sealant layer Can be obtained.

The perspective view of the paper cup which concerns on embodiment of this invention. (A) is the perspective view which looked at the exterior sleeve of FIG. 1 from upper direction, (B) is the perspective view which looked at the exterior sleeve of FIG. 1 from the downward direction. The perspective view of the container main body of FIG. Sectional drawing of the laminated body which comprises the side wall of the container main body of FIG.

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

  As shown in FIG. 1, the paper cup 1 includes a cup-shaped container body 11 and an outer sleeve 21 that covers the outer peripheral surface of the container body 11, and the body portion of the paper cup 1 has a double structure. Both the container body 11 and the outer sleeve 21 are formed from a paper blank board having a paper layer 32 and a sealant layer 34.

As shown in FIGS. 2 (A) and 2 (B), the container body 11 has an inverted frustoconical shape with an open upper end, and includes a cylindrical side wall 12 and a circular bottom 13 that closes the lower end of the side wall 12. Yes. An outward curl 14 is formed on the upper edge of the side wall 12. As shown in FIG. 3, the outer sleeve 21 has a cylindrical shape, and an inward curl 22 is formed on the lower edge. The basis weight of the outer sleeve 21 is 200 g / m ² to 350 g / m ² .

  The layer structure of the laminate 31 forming the side wall 12 of the container body 11 of the present invention is formed of a paper layer 32, a resin layer (a layer containing a cyclic polyolefin) 33, and a sealant layer 34, as shown in FIG. Has been. In this laminated body 31, the sealant layer 34 is arrange | positioned inside. The laminated body 31 may be applied to the bottom wall 13 in addition to the sidewall 12.

A cup base paper is used as the paper layer 32. The basis weight can be 180 g / m ² to 280 g / m ² .

  A cyclic polyolefin resin is used as the resin layer 33. The cyclic polyolefin resin includes a ring-opening metathesis polymer (COP) obtained by polymerizing a cyclic olefin by a metathesis ring-opening polymerization reaction, and a copolymer of a cyclic olefin and an α-olefin (chain olefin), that is, a cyclic olefin copolymer (COC). Is included.

  As the cyclic olefin, any cyclic hydrocarbon having an ethylenically unsaturated bond and a bicyclo ring can be used, particularly those having a bicyclo [2.2.1] hept-2-ene (norbornene) skeleton. preferable.

Specifically, bicyclo [2.2.1] hept-2-ene and derivatives thereof, tricyclo [4.3.0.1 ^2.5 ] -3-decene and derivatives thereof, tricyclo [4.4.0 .1 ^2.5 ] -3-undecene and derivatives thereof, tetracyclo [4.4.0.1 ^2.5 1 ^7.10 ] -3-dodecene and derivatives thereof, pentacyclo [6.5.1.1 ^{. 6} . 0 ^2.7 . 0 ^9.13 ] -4-pentadecene and its derivatives, pentacyclo [7.4.0.1 ^2.5 . 1 ^9.12 . 0 ^8.13 ] -3-pentadecene and its derivatives, pentacyclo [6.5.1.1 ^3.6 . 0 ^2.7 . 0 ^9.13 ] -4,10-pentadedecadiene and its derivatives, pentacyclo [8.4.0.1 ^2.5 . 1 ^9.12 . 0 ^8.13 ] -3-hexadecene and derivatives thereof, but are not limited thereto. The cyclic olefin may have a polar group such as an ester group, a carboxyl group, and a carboxylic anhydride group as a substituent.

  As the α-olefin copolymerized with the cyclic olefin, ethylene and an α-olefin having 3 to 20 carbon atoms can be used. Specifically, ethylene, propylene, 1-butene, 1-pentene, 3-methyl Examples include -1-butene, 1-hexene, 4-methyl-1-pentene, and preferably ethylene.

  The production of the ring-opening metathesis polymer is not particularly limited as long as it is a known ring-opening metathesis polymerization reaction, and can be produced by ring-opening polymerization of the above cyclic olefin using a polymerization catalyst.

  In the production of the cyclic olefin copolymer, 25 to 45 mol% of α-olefin and 55 to 75 mol% of cyclic olefin are randomly polymerized using a single site catalyst such as a metallocene catalyst or a multisite catalyst. Is made by

  Several ring-opening metathesis polymers and cyclic olefin copolymers preferably used in the present invention are commercially available. For example, “ZEONOR (R)” manufactured by Nippon Zeon Co., Ltd. and “TOPAS (R) manufactured by Polyplastics Co., Ltd. ) "And the like.

  The layer configuration of the co-extruded resin of the resin layer 33 may be a two-layer or three-layer configuration. Specifically, it may contain a multilayer structure of cyclic polyolefin resin, or other resins such as low density polyethylene, medium density polyethylene, polypropylene, polyamide, ethylene vinyl alcohol and the like.

  The thickness of the resin layer 33 is preferably 10 μm to 30 μm, and the thickness of the cyclic polyolefin layer is particularly preferably 10 μm or more.

  The sealant layer 34 is preferably a material suitable for melt extrusion processing such as polyethylene and polypropylene, and uses a heat-sealable thermoplastic resin. The thickness is preferably 15 μm to 40 μm.

  Since the laminate 31 of the present invention uses a cyclic polyolefin resin as the resin layer 33, the laminate 31 has excellent moisture resistance and aroma retention. For this reason, there is little deterioration of the content in storage and it can be stored for a long period of time. In addition, the use of a barrier film in which a metal foil, a metal or an inorganic oxide is vapor-deposited on a plastic film can be used to prevent moldability from being lowered, and curl and whisker can be prevented, and the resin layer 33 can be made thin.

  In order to assemble the paper cup 1, first, the both ends of the blank side wall 12 made of the laminate 31 manufactured by the above method are overlapped and bonded to form a cylinder. And after attaching the bottom wall 13 which bent the outer periphery to the lower end of the side wall 12, the outward curl 14 is formed in the upper edge, and the container main body 11 is created. Similarly, both end portions of the outer sleeve 21 are overlapped and bonded to form a cylindrical shape with an inward curl 22 at the lower end portion. Thereafter, an adhesive is applied in the circumferential direction with a width of about 20 mm on the lower outer peripheral surface of the outward curl 14 of the container body 11 to provide a circumferential adhesive region, and the inside of the outer sleeve 21 formed in a cylindrical shape. The container body 11 is inserted into the heat insulating container 1. Synthetic glue, for example, ethylene-vinyl acetate copolymer glue (EVA glue) is applied to the circumferential adhesive region. As the paste to be used in this manner, a known paste can be used. However, when the content is food, a paste having less odor is preferable.

  When the container main body 11 is inserted into the outer sleeve 21, the container main body 11 and the outer sleeve 21 come closer to each other toward the upper part and come into contact with each other at the uppermost end. The part where the space | interval near this upper end becomes narrow adhere | attaches in the circumferential direction adhesion | attachment area | region. The inward curl 22 of the outer sleeve 21 contacts the outer surface of the lower end portion of the container body 11, and an annular gap is formed between the inward curl 22 and the circumferential adhesive region. This void plays a role of heat insulation.

Next, specific examples of the present invention will be described in detail.
<Example 1>
A molten cyclic polyolefin was extruded into a paper layer composed of a cup base paper having a basis weight of 260 g / m ² with a thickness of 20 μm through a polyimide adhesive. Thereafter, melt low density polyethylene was melt-extruded with a thickness of 25 μm to provide a sealant layer. Sheets laminated by the above method were punched into a blank shape, processed by a cup molding machine, and used as the side wall 12 and the bottom wall 13 of the container body 11.
The outer sleeve 21 was made by using 310 g / m ² of coated cardboard, punched into a blank shape, and formed into a sleeve.
Finally, the container body 11 was inserted into the outer sleeve 21, and the paper cup 1 was manufactured by bonding with the circumferential adhesive region.

<Comparative Example 1>
A melt layer of melt low density polyethylene was melt-extruded to a thickness of 45 μm on a paper layer made of cup base paper having a basis weight of 260 g / m ² to provide a sealant layer. A paper cup 1 was manufactured in the same manner as in Example 1 except for this.

<Comparative example 2>
A biaxially stretched polyethylene terephthalate film (hereinafter referred to as a silicon oxide vapor-deposited PET film) 12 μm having a silicon oxide vapor-deposited layer on the surface as a barrier film is melted on a paper layer comprising a cup base paper having a basis weight of 260 g / m ² , and a low-density polyethylene 15 μm And sandwiched with sandwich. Thereafter, an isocyanate-based adhesive was coated on the surface of the silicon oxide vapor-deposited PET film where the silicon oxide vapor-deposited layer was not formed, and a melt low-density polyethylene was melt-extruded to a thickness of 20 μm to provide a sealant layer. A paper cup 1 was manufactured in the same manner as in Example 1 except for this.

(Blank curl measurement)
After punching the sheet made of the laminate 31 constituting the side wall 12 of the container body 11 manufactured in Example 1 and Comparative Examples 1 and 2 into a blank shape, the blank was placed in a horizontal place and the maximum curl height was measured. .
When the maximum curl height was 5 mm or less, “◯” was judged, and when it was 5 mm or more, “x” was judged.

(Forming evaluation method)
100 sheets of the container body 11 were produced by a cup molding machine using the sheet made of the laminate 31 constituting the side wall 12 and the bottom wall 13 of the container body 11 manufactured in Example 1 and Comparative Examples 1 and 2, and the molding was poor. The presence or absence of occurrence was confirmed. A case where no defective molding occurred was determined as “◯”, and a case where a molding defect occurred was determined as “x”.

(Dampproofness evaluation method)
The ramen powder soup is stored in the paper cup 1 manufactured in Example 1 and Comparative Examples 1 and 2, sealed with a lid made by the following method, and stored for 1 month in an atmosphere of 40 ° C. × 90 wt%. The material was opened and it was observed whether the powder soup was liquefied. The case where it was not liquefied was judged as “◯”, and the case where it was liquefied was judged as “x”.

A method for manufacturing the lid will be described. 9 μm of aluminum foil is sandwich-laminated with 15 μm of melted low density polyethylene on a paper layer made of a piece of art paper having a basis weight of 79.1 g / m ² , and then an easy peel sealant (with an isocyanate adhesive on the back surface of the aluminum foil) 7601DA (Toray Film Processing Co., Ltd., thickness 30 μm) was dry laminated to produce a lid material.

(Scent retention evaluation method)
A container sealed with the above-mentioned lid material was prepared in the paper cup 1 produced in Example 1 and Comparative Examples 1 and 2, and stored together with a pyrethroid insecticide in a 40 ° C. × 90 wt% atmosphere for one month. Thereafter, the container was taken out, the lid was opened, and the presence or absence of odor in the container was confirmed. The case where no odor was felt was judged as “◯”, and the case where the odor was felt was judged as “x”.

  The results are shown in Table 1.

  From Table 1, in the paper cup of Example 1, curl and molding failure in a blank state were not observed, and both moisture resistance and aroma retention were good. In the paper cup of Comparative Example 1, curl and moldability in the blank state were good, but moisture resistance and aroma retention were insufficient. Further, in the paper cup of Comparative Example 2, moisture resistance and fragrance retention were good, but curling and molding failure in a blank state were observed.

  In addition, the paper cup 1 of this invention is not limited to the said embodiment, For example, you may employ | adopt the paper cup 1 which does not mount the exterior sleeve 21. FIG.

DESCRIPTION OF SYMBOLS 1 Paper cup 12 Side wall 13 Bottom wall 31 Laminated body 32 Paper layer 33 Layer containing cyclic polyolefin (resin layer)
34 Sealant layer

Claims (6)

A paper cup having a paper side wall and a bottom wall provided with a paper layer and an inner sealant layer, and having an outward curl portion formed on an upper edge of the side wall,
Between the front SL paper layer and the sealant layer, paper cups, characterized in that it is formed by a laminate having only a resin layer containing a cyclic polyolefin laminated on the paper layer through the adhesive polyimide .   The paper cup according to claim 1, wherein the side wall has a double structure including a cylindrical outer sleeve that covers an outer peripheral surface of the side wall.   The cyclic polyolefin is selected from the group consisting of a ring-opening metathesis polymer obtained by polymerizing a cyclic olefin by a metathesis ring-opening polymerization reaction, and a copolymer of a cyclic olefin and an α-olefin. 2. The paper cup according to 2. The cyclic olefin is
Bicyclo [2.2.1] hept-2-ene,
Tricyclo [4.3.0.1 ^2.5 ] -3-decene,
Tricyclo [4.4.0.1 ^2.5 ] -3-undecene,
Tetracyclo [4.4.0.1 ^2.5 1 ^7.10 ] -3-dodecene,
Pentacyclo [6.5.1.1 ^3.6 . 0 ^2.7 . 0 ^9.13 ] -4-pentadecene,
Pentacyclo [7.4.0.1 ^2.5 . 1 ^9.12 . 0 ^8.13 ] -3-pentadecene,
Pentacyclo [6.5.1.1 ^3.6 . 0 ^2.7 . 0 ^9.13 ] -4,10-pentadegadiene,
Pentacyclo [8.4.0.1 ^2.5 . 1 ^9.12 . The paper cup according to claim 3, wherein the paper cup is selected from the group consisting of 0 ^8.13 ] -3-hexadecene and derivatives thereof.   The paper cup according to any one of claims 1 to 4, wherein a thickness of the layer containing the cyclic polyolefin is 10 µm to 30 µm. Having a side wall and a bottom wall made of paper and a sealant layer to the paper layer and the inner paper mosquito Tsu according to any one of claims 1 to outwardly curled portion is formed 5 in the upper edge of the side wall A manufacturing method of
Extruded molten cyclic polyolefin to the paper layer through a polyimide adhesive,
A method for producing a paper cup, comprising: a sheet production step of extruding molten low density polyethylene onto the molten cyclic polyolefin to form the sealant layer.

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