JP4888208B2 - Liquid paper container with spout - Google Patents

Description

  The present invention relates to a paper container for packaging various liquid foods, and more particularly to a liquid paper container equipped with a stopper.

In recent years, a large amount of liquid paper containers with caps have been used as packaging containers for liquor, shochu, various seasonings, etc., to make it easier to take out the contents. The paper container body of the container has the following structure: (outer side) thermoplastic resin layer / paper layer (basis weight 350 to 400 g / m ² ) / adhesive resin layer / gas barrier layer / adhesive layer / thermoplastic resin layer (wetted side) Made of a laminated material or a blank obtained by punching a laminated material (outside) thermoplastic resin layer / paper layer (basis weight 350 to 400 g / m ² ) / thermoplastic resin layer (wetted side) into a predetermined shape Generally, linear low-density polyethylene resin and low-density polyethylene resin are used for the thermoplastic resin layer on the wetted side, but flavor components derived from the contents during the storage period Will be absorbed, and the initial flavor will be damaged. There is a problem such as accidentally. In order to improve these problems, a liquid paper container using a polyester-based resin for the thermoplastic resin layer on the liquid contact side has been proposed (for example, see Patent Document 1).
JP-A-5-162737

  However, the proposed liquid paper container has a drawback that the sealing property of the polyester resin used on the inner surface is poor, a sealing failure is likely to occur during box making, and the contents leak.

  An object of the present invention is a liquid paper container with a cap equipped with a cap and a spout, which is free from leakage from the heat-sealed portion of the spout and adsorbs components derived from the content. The object is to provide a liquid paper container with a small number of stoppers.

  According to the first aspect of the present invention, there is provided a cap for a liquid paper container body made of a laminated material having a paper layer in the middle, an outer surface resin layer on one outermost side, and a sealant layer on the other outermost side. In the liquid paper container with a cap, in which a cap made of spout is attached, the side of the sealant layer that contacts the single or content of the cyclic olefin resin is the cyclic olefin resin layer, and the outermost side on the opposite side is the polyethylene resin layer Consisting of multi-layer coextrusion resin, the spout is connected at least to the lower end of the hollow tubular part on the liquid paper container body side, and a seal part protruding outward from the outer periphery is connected continuously, and an external thread part protruding upward from the outer periphery is connected continuously A liquid paper container with a cap is characterized in that the surface of the seal portion on the male screw side and the inner surface of the liquid paper container body are heat-sealed through an adhesive film. It is.

  The invention according to claim 2 of the present invention is the invention according to claim 1, wherein the spout is made of a polyethylene resin, and the adhesive film has a polyethylene resin layer on one outermost side and a cyclic olefin on the other outermost side. It is composed of a multilayer coextruded film as a resin layer, the polyethylene resin layer and the spout seal portion are heat-sealed, and the cyclic olefin resin layer and the inner surface of the liquid paper container body are heat-sealed. It is a liquid paper container with a cap.

  The liquid paper container with a stopper of the present invention has a paper layer in the middle, an outer surface resin layer on one outermost side, and a cap on the liquid paper container body made of a laminated material having a sealant layer on the other outermost side. In the liquid paper container with a cap, in which a cap made of spout is attached, the side of the sealant layer that contacts the single or content of the cyclic olefin resin is the cyclic olefin resin layer, and the outermost side on the opposite side is the polyethylene resin layer Consisting of multi-layer coextrusion resin, the spout is connected at least to the lower end of the hollow tubular part on the liquid paper container body side, and a seal part protruding outward from the outer periphery is connected continuously, and an external thread part protruding upward from the outer periphery is connected continuously Since the male screw part side surface of the seal part and the inner surface of the liquid paper container main body are heat-sealed via an adhesive film, the contents are filled and sealed, Adsorption of components derived from the contents is very small, and the spout is made of a polyethylene resin, and the adhesive film is a multilayer copolymer in which one outermost side is a polyethylene resin layer and the other outermost side is a cyclic olefin resin layer. Since the polyethylene resin layer and the spout seal portion are heat-sealed, and the cyclic olefin resin layer and the inner surface of the liquid paper container main body are heat-sealed, the spout seal portion and the liquid paper The inner surface of the container body adheres firmly and there is no leakage of the contents.

  The liquid paper container with a stopper of the present invention will be described below along the embodiment. FIG. 2A is a side sectional view showing an embodiment of a laminated material used for the liquid paper container with a stopper of the present invention, and the laminated material (10) is formed in order of the outer surface resin layer (12) in the thickness direction. , A paper layer (11), an adhesive resin layer (13), a gas barrier layer (14), an adhesive layer (15), and a sealant layer (16). It is a sectional side view which shows embodiment, Laminate material (10 ') is an outer surface resin layer (12), a paper layer (11), an adhesive resin layer (13), a gas barrier layer (14), adhesion in order in the thickness direction. The agent layer (15) and the sealant layer (16 ') are laminated, and the sealant layer (16') has a two-layer constitution of a polyethylene resin layer (17) and a cyclic olefin resin layer (18). ing.

  In the laminated material (10, 10 '), a reinforcing film layer made of a biaxially stretched polyester film or the like is laminated between the gas barrier layer (14) and the adhesive layer (15) via the adhesive layer. good.

For the paper layer (11), a paperboard having a basis weight of 350 to 450 g / m ² is generally used.

  Generally, a low density polyethylene resin or a linear low density polyethylene resin is used for the outer surface resin layer (12). Thicknesses of 10 to 30 μm are often used, and lamination is carried out by a known melt extrusion lamination method.

  For the adhesive resin layer (13), any of polyethylene resin (PE resin), ethylene / methacrylic acid copolymer resin (EMAA resin), ethylene / acrylic acid copolymer resin (EAA resin), ionomer resin, etc. Such resin is used.

  The gas barrier layer (14) is made of a material having a single layer structure or a laminated structure. Examples of the material having a single layer structure include a biaxially stretched polyester film, a biaxially stretched nylon film, an ethylene / vinyl alcohol copolymer film, An aluminum foil is used, and as a laminated material, an aluminum vapor-deposited polyester film, an inorganic oxide vapor-deposited polyester film such as aluminum oxide or silicon oxide, or the like is used, and excellent gas barrier properties can be imparted.

For the adhesive layer (15), a polyurethane-based adhesive is usually used, and a two-component mixed adhesive that is used by mixing a main agent having a hydroxyl group and a curing agent having an isocyanate group is usually used. Is done. As the lamination method, a dry lamination method is used, and the coating amount is preferably 1 to 5 g / m ² (dry state).

  The sealant layer (16) is made of a cyclic olefin resin alone.

  The sealant layer (16 ') is made of a two-layer coextruded resin having a polyethylene resin layer (17) and a cyclic olefin resin layer (18). In this case, the surface of the cyclic olefin resin layer (18) is always the content. It is necessary to form so as to be on the side in contact with the object.

  As described above, the side of the sealant layer (16, 16 ') that is in contact with the contents is always made of a cyclic olefin resin, so that it is difficult for components such as scents derived from the contents to be adsorbed. Good quality can be maintained.

  FIG. 3 is a side sectional view showing an embodiment of an adhesive film used in the liquid paper container with a stopper of the present invention. The adhesive film (20) includes a cyclic olefin resin layer (21) and a polyethylene resin layer ( 22), and the production method is to form a film by extruding a cyclic olefin resin and a polyethylene resin by a two-layer coextrusion method.

  Examples of the cyclic olefin resin used for the sealant layer (16, 16 ') and the adhesive film (20) include ethylene / cyclic olefin random copolymer resin, cyclic olefin ring-opening copolymer hydride resin, An ethylene / cyclic olefin random copolymer graft-modified resin, a cyclic olefin ring-opening copolymer graft-modified resin, and the like can be used.

  FIG. 1A is a perspective view showing an embodiment of a liquid paper container with a stopper of the present invention, and the liquid paper container with a stopper (1) is made by using the laminated material (10). A cap (4) and a spout (3) comprising a spout (5) are attached to the liquid paper container main body (2), and (b) is an enlarged sectional view showing the structure of part A of (a). The spout (5) has a seal portion (5c) protruding outward from the outer periphery at the lower end of the hollow tubular portion (5a) on the liquid paper container main body side, and a male screw portion (5b) protruding outward from the outer periphery upward. Further, the surface of the seal portion (5c) on the male screw portion (5b) side and the sealant layer (16) of the laminated material (10) are formed of a cyclic olefin resin layer (21). Adhesive fill consisting of a two-layer coextruded film with a polyethylene resin layer (22) It is thermally fused through (20). In this case, it is necessary to heat-seal so that the polyethylene resin layer (22) surface of the adhesive film (20) is on the seal portion (5c) side of the spout (5).

  The spout (5) of the plug (3) is made of polyethylene resin, and the cap (4) is made of polyethylene resin or polypropylene resin.

  The liquid paper container with a stopper of the present invention is not limited to the gable top type, and includes a flat top type.

  Below, the liquid paper container with a stopper of this invention is demonstrated in detail along a specific Example.

As the paper layer (11), a board having a basis weight of 400 g / m ² is used, as the resin of the outer surface resin layer (12), a low density polyethylene resin (LDPE) is used, and as the resin of the adhesive resin layer (13), An ethylene / methacrylic acid copolymer (EMAA) resin is used, a 7 μm thick aluminum foil is used as the gas barrier layer (14), and a 12 μm thick biaxially stretched polyester film (PET film) is used as the reinforcing film layer. Use polyurethane adhesive as the adhesive layer (15), ethylene / cyclic olefin random copolymer resin as the sealant layer (16) resin, LDPE (20μ) / paperboard (400g) / m ²⁾ / EMAA resin (25.mu.) / aluminum foil (7 microns) / polyurethane adhesive (3g / m ²⁾ / PET film (12 [mu) Create polyurethane adhesive (3 g / m ²⁾ / ethylene-cyclic olefin random copolymer resin (60 microns) of the structure of the multilayer material (10), further, as the spout (3), a polyethylene resin cap ( 4) and spout (5) were prepared, and a two-layer coextrusion with a total thickness of 40 μm of ethylene / cyclic olefin random copolymer resin layer / polyethylene resin layer = 50/50 (thickness ratio) as an adhesive film (20) A film was created. Using the prepared materials, a gable top type liquid paper container with a stopper of the present invention having an internal volume of 900 ml having the shape and structure shown in FIG. 1 was prepared.

  In Example 1, as the resin of the sealant layer (16), an ethylene / cyclic olefin random copolymer resin layer / polyethylene resin layer = 70/30 (thickness ratio) of a two-layer coextruded resin having a total thickness of 60 μm was used. In the same manner, a liquid paper container with a stopper of the present invention was prepared.

  Hereinafter, comparative examples of the present invention will be described.

  A liquid paper container with a stopper for comparison was prepared in the same manner as in Example 1 except that low-density polyethylene resin (LDPE) was used as the resin for the sealant layer.

<Evaluation>
The spout heat-sealing quality when producing the liquid paper containers with plugs of Examples 1 and 2 and the liquid paper container with plugs of Example 3 for comparison was evaluated. Furthermore, the amount of limonene adsorbed on each of the stoppered liquid paper containers and the quality of the contents preservability were evaluated by the following methods. The results are shown in Table 1.
(1) Evaluation method of limonene adsorption amount Each pre-filled liquid paper container was weighed before filling with limonene, sealed with 100 ml of limonene, sealed and stored at 40 ° C for 1 week. The weight of the liquid paper container with a stopper was measured, and the amount of limonene adsorbed was evaluated from the weight change.
(2) Evaluation method of contents storage stability Each bottle of stoppered liquid paper container is filled and sealed with 200 ml of distilled water, and after storage at 60 ° C for 24 hours, the taste of distilled water inside is sensory-evaluated, The quality was evaluated.

表１に示すように、実施例１及び実施例２の本発明の口栓付き液体用紙容器は、スパウトの熱融着性は良好であり、リモネンのシーラント層への吸着量は非常に小さく、また中に充填した蒸留水の６０℃、２４時間保存後の味覚も良好であった。一方、実施例３の比較用の口栓付き液体用紙容器のスパウトの熱融着性は悪くて装着できなかった。また、リモネンのシーラント層への吸着量も大きく、中に充填した蒸留水の６０℃、２４時間保存後の味覚も、ポリエチレン臭があり不良であった。

As shown in Table 1, the spouted liquid paper containers of the present invention of Examples 1 and 2 have good heat-fusability of the spout, and the amount of limonene adsorbed on the sealant layer is very small. Moreover, the taste after storing for 24 hours at 60 ° C. was also good. On the other hand, the spout of the liquid paper container with a stopper for comparison in Example 3 was poor and could not be attached. Further, the amount of limonene adsorbed on the sealant layer was large, and the taste of the distilled water filled therein after storage at 60 ° C. for 24 hours was also poor due to polyethylene odor.

(A) is a perspective view which shows one Embodiment of the liquid paper container with a stopper of this invention, (b) is an expanded sectional view which shows the structure of A part of (a). (A) is a sectional side view which shows one Embodiment of the laminated material used for the liquid paper container with a stopper of this invention, (b) is a sectional side view which shows other embodiment of a laminated material. It is a sectional side view which shows one Embodiment of the film for adhesion | attachment used for the liquid paper container with a stopper of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Liquid paper container with cap 2 ... Liquid paper container main body 3 ... Plug 4 ... Cap 5 ... Spout 5a ... Hollow tubular part 5b ... Male screw part 5c ... Seal part 10, 10 '... Laminate material 11 ... Paper layer 12 ... Outer surface resin layer 13 ... Adhesive resin layer 14 ... Gas barrier layer 15 ... Adhesive layers 16 and 16 '... Sealant layer 17 ... Polyethylene resin layer 18 ... Cyclic olefin resin layer 20 ... Adhesive film 21 ... Cyclic olefin resin layer 22 ... Polyethylene resin layer

Claims (2)

  A cap made of a cap and spout is attached to a liquid paper container body made of a laminated material having a paper layer in the middle, an outer resin layer on one outermost side, and a sealant layer on the other outermost side. In the liquid paper container with a stopper, the sealant layer is made of a multilayer coextruded resin in which the cyclic olefin resin alone or the side in contact with the contents is a cyclic olefin resin layer and the outermost side on the opposite side is a polyethylene resin layer, and the spout is at least A seal portion projecting outward from the outer periphery to the lower end of the liquid tubular container body side of the hollow tubular portion, and an external thread portion projecting outward from the outer periphery to the upper side, and the external thread portion of the seal portion A liquid paper container with a cap, wherein the side surface and the inner surface of the liquid paper container main body are heat-sealed through an adhesive film.   The spout is made of a polyethylene resin, and the adhesive film is made of a multilayer coextruded film in which one outermost side is a polyethylene resin layer and the other outermost side is a cyclic olefin resin layer, and a seal portion between the polyethylene resin layer and the spout 2. The liquid paper container with a cap according to claim 1, wherein the cyclic olefin resin layer and the inner surface of the liquid paper container body are heat-sealed.

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