JP2007238127A - Paper container for liquid and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a paper container for liquid which is laminated with a stable adhesion strength by thermofusion extruding an adhesive resin layer 5 at least between a barrier layer 3 and an inside sealant layer 4 and which has no possibility of the adhesive agent component, etc. of a conventional urethane adhesive agent layer to liquate out into a stored content as to a rectangular parallelepiped container for liquid with a flat or a gable roof shaped top face made of a laminated paper material laminating at least an outer face paper material layer 2, a barrier layer 3, and an inside sealant layer 4 for storing juice, seasoning or alcohol. <P>SOLUTION: This relates to a paper container for liquid and its manufacturing method. In manufacturing the paper container for liquid, an adhesive resin layer 5 is thermofusion extruded and laminated after an ozone process d or/and a corona process d is/are performed on each face contacting the adhesive resin layer 5 of at least a barrier layer 3 and an inside face sealant layer 4. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention is a rectangular parallelepiped liquid paper container having a flat top surface or a gabled roof shape made of a paper laminate material that contains juice, seasonings, liquor, etc. The present invention relates to a liquid paper container and a method for manufacturing a liquid paper container in which an agent component or the like is not likely to elute into contained contents.

  Conventionally, a top plate group a, a, a, a and side plates b, b, b, b, as shown in FIGS. 3A and B, for example, made of a paper laminate material that contains juice, seasonings, liquor, etc. In general, a liquid paper container having an inner volume of 200 to 3000 ml having a flat top surface or a gabled roof shape and having an inner volume of 200 to 3000 ml, which is formed by connecting bottom plate groups c, c, c, and c, is widely used. Yes.

For the conventional paper lamination material of the liquid paper container shown in FIGS. 3A and 3B, for example, as shown in FIG. 2A, the surface resin layer 6 such as polyethylene (PE) is laminated on the surface and printed beautifully. A suitable outer paper material layer 2 of 150 to 550 g / m ² having excellent strength and shape retention, and a barrier such as 12 to 25 μm polyester (PET) with ceramic (SiO _x ) deposition e having various barrier properties. The layer 3 and the inner sealant layer 4 such as 30-100 μm low density polyethylene (LDPE) excellent in heat-fusibility and sealing properties are bonded between the outer paper material layer 2 and the barrier layer 3 as described later. The heat-resistant resin layer 5 is laminated by hot melt extrusion (or via a urethane-based adhesive layer 7 described later), and between the barrier layer 3 and the inner surface sealant layer 4, there are lamination strength and workability. excellent 5g / m ² about Paper laminated materials with excellent strength, shape retention, various barrier properties, heat-sealing properties, and sealing properties, which are laminated by the usual dry lamination method, etc., through the adhesive layer 7 of the urethane are generally widely used. ing.

3A and 3B, for example, as shown in FIG. 2B, the surface resin layer 6 similar to that described above is laminated on the surface and printed beautifully. A barrier layer 3 such as 12-25 μm polyester (PET) in which an outer paper material layer 2 similar to that described above having excellent shape retention and an aluminum foil 8 having various barrier properties are laminated via an appropriate adhesive layer. Between the outer paper material layer 2 and the barrier layer 3, the adhesive resin layer 5, which will be described later, is hot-melt extruded. (Or via a urethane-based adhesive layer 7 described later), and between the barrier layer 3 and the inner surface sealant layer 4, 5 g / m ² is similarly excellent in lamination strength and workability. Through a urethane-based adhesive layer 7 In general, paper laminated materials that are laminated by a mining method and similarly excellent in strength, shape retention, various barrier properties, heat fusion properties, and sealing properties are widely used.

However, in the conventional liquid paper container shown in FIGS. 3A and 3B, for the paper laminated material shown in FIG. 2A and for the paper laminated material shown in FIG. 2B, urethane-based adhesives having excellent lamination strength and workability, respectively. Although it is a paper laminated material that is laminated through the agent layer 7 and has excellent strength, shape retention, various barrier properties, heat-sealing properties, and sealing properties, the gap between each barrier layer 3 and the inner surface sealant layer 4 There is a problem in the lamination with a urethane adhesive layer 7 of about 5 g / m ² , and the liquid paper container shown in FIGS. 3A and 3B has a flat top surface or a gable roof-shaped rectangular parallelepiped liquid paper container. When stored for a long period of time, containing juice, seasonings, alcoholic beverages, etc., the adhesive component of the urethane adhesive layer 7 of about 5 g / m ² has the respective heat-fusibility and sealing properties. Passed through the excellent inner sealant layer 4 There is a risk of leaching into the contents, and even if the amount is small, there is a risk of damaging the taste of stored juices, seasonings, and alcoholic beverages.

2A and 2B described above, a method of laminating an adhesive resin layer 5 (described later) by hot-melt extrusion between the outer paper material layer 2 and the barrier layer 3. In addition to this, when laminated by a normal dry lamination method or the like through a urethane adhesive layer 7 of about 5 g / m ² having excellent lamination strength and workability, this urethane type of about 5 g / m ² Since the adhesive components of the adhesive layer 7 are blocked by the barrier layers 3 having various barrier properties, they are eluted into the contained contents and impair the taste of juice, seasonings, alcoholic beverages, etc. There was no fear.

Accordingly, an object of the present invention is a rectangular parallelepiped liquid paper container having a flat upper surface or a gabled roof shape, which is made of a paper laminated material that contains juice, seasonings, liquor, etc. The adhesive component of the urethane adhesive layer 7 that is not laminated between the barrier layer 3 of the laminated material and the inner surface sealant layer 4 via the urethane adhesive layer 7 of about 5 g / m ² , An object of the present invention is to provide a liquid paper container and a method for manufacturing the liquid paper container that are not likely to elute into the contained contents.

  The liquid paper container of the present invention comprises a top plate group a, a, a, a and side plates b, b, made of a paper laminate material in which at least an outer paper material layer 2, a barrier layer 3, and an inner sealant layer 4 are laminated. FIG. 1 shows a rectangular parallelepiped liquid paper container having a flat upper surface or a gable roof shape as shown in FIGS. 3A and 3B, in which b, b and bottom plate groups c, c, c, c are connected. As shown, a liquid paper container is characterized in that an adhesive resin layer 5 is laminated by hot melt extrusion between at least a barrier layer 3 and an inner surface sealant layer 4.

In the liquid paper container of the present invention, a beautiful printing was performed by laminating a surface resin layer 6 such as polyethylene (PE) on the surface, similar to the conventional paper laminating material shown in FIGS. 2A and 2B. An appropriate outer paper material layer 2 of 150 to 550 g / m ² having excellent strength and shape retention, and an aluminum foil 8 (not shown) with ceramic (SiO _x ) vapor deposition e having various barrier properties (or not shown) are appropriately used. Barrier layer 3 such as polyester (PET) of 12 to 25 μm and an inner surface sealant layer such as low density polyethylene (LDPE) of 30 to 100 μm excellent in heat-sealing and sealing properties. 4, as shown in FIG. 1, between the outer paper material layer 2 and the barrier layer 3, the adhesive resin layer 5, which will be described later, is hot-melt extruded (or illustrated) as in the conventional case described above. Not the aforementioned urethane system An ethylene-methacrylic acid copolymer (EMAA) or wire having a good heat-fusability and heat-adhesive property at least between the barrier layer 3 and the inner surface sealant layer 4 is laminated. An adhesive resin layer 5 such as a low-density polyethylene (LLDPE) or an ethylene-vinyl acetate copolymer (EVA) is melted by heat, extruded into a film of 10 to 60 μm, and laminated (referred to as extrusion lamination). The same)
A top plate group a, a, a, a and a side plate b made of a paper laminate material containing at least an outer paper material layer 2, a barrier layer 3 and an inner sealant layer 4 and containing juice, seasonings, liquors and the like. , B, b, b and a bottom plate group c, c, c, c, which are connected to each other in a rectangular parallelepiped liquid paper container having a flat upper surface or a gable roof shape on the upper surface, and at least a barrier layer 3. The adhesive resin layer 5 is hot melt extruded and laminated between the inner sealant layer 4 and the inner surface sealant layer 4 and is not laminated via a urethane adhesive layer 7 of about 5 g / m ^2. It is possible to obtain a liquid paper container in which the adhesive component of the adhesive layer 7 of the system is not likely to elute into the contained contents, and does not impair the taste of the contained and stored juice, seasoning, liquor, etc. it can.

The method for producing a liquid paper container of the present invention is a liquid paper container in which an adhesive resin layer 5 is laminated by hot melt extrusion between at least the barrier layer 3 and the inner surface sealant layer 4 described above with reference to FIG. As shown in the drawing, at least the surfaces of the barrier layer 3 and the inner surface sealant layer 4 in contact with the adhesive resin layer 5 are each subjected to either or both of ozone treatment d and corona treatment d, and then the adhesive resin. A method for manufacturing a liquid paper container, wherein the layer 5 is laminated by hot melt extrusion.

In the manufacturing method of the liquid paper container of the present invention, when the adhesive resin layer 5 is hot-melt extruded and laminated between at least the barrier layer 3 and the inner surface sealant layer 4 described above, as shown in FIG. At least the surface of the barrier layer 3 and the inner surface sealant layer 4 that are in contact with the adhesive resin layer 5, respectively, was subjected to either ozone treatment d or corona treatment d for stabilizing the adhesive strength of the adhesive resin. Later, after both ozone treatment d and corona treatment d were applied, ethylene-methacrylic acid copolymer (EMAA), linear low density polyethylene (LLDPE) and By thermally melting the adhesive resin layer 5 such as an ethylene-vinyl acetate copolymer (EVA) and extruding it into a film of 10 to 60 μm, and laminating it,
A top plate group a, a, a, a and a side plate b made of a paper laminate material containing at least an outer paper material layer 2, a barrier layer 3 and an inner sealant layer 4 and containing juice, seasonings, liquors and the like. , B, b, b and a bottom plate group c, c, c, c, which are connected to each other in a rectangular parallelepiped liquid paper container having a flat upper surface or a gable roof shape on the upper surface, and at least a barrier layer 3. The adhesive resin layer 5 can be hot melt extruded between the inner surface sealant layer 4 and the inner surface sealant layer 4 to obtain a method for manufacturing a liquid paper container that can be laminated in a state where the adhesive strength of the adhesive resin is stabilized. .

  As described above, in the liquid paper container and the manufacturing method of the liquid paper container of the present invention, at least the outer paper material layer 2, the barrier layer 3, and the inner sealant layer 4 are laminated, and the paper lamination that contains juice, seasonings, alcoholic beverages, and the like. The upper surface plate group a, a, a, a and the side surface plates b, b, b, b and the bottom surface plate group c, c, c, c, which are made of material, are connected in a continuous manner. A gable roof-shaped rectangular parallelepiped liquid paper container in which an adhesive resin layer 5 is hot-melt extruded between at least the barrier layer 3 and the inner surface sealant layer 4 and laminated in a state where the adhesive strength is stabilized. It is possible to provide a liquid paper container and a method for manufacturing the liquid paper container in which the adhesive component of the conventional urethane-based adhesive layer 7 and the like that can be dissolved into the contained contents can be provided.

In the method for manufacturing a liquid paper container of the present invention, the ozone treatment d applied to at least the surfaces of the barrier layer 3 and the inner surface sealant layer 4 that are in contact with the adhesive resin layer 5, respectively, has an ozone concentration of 5 to 30 g / Nm ³ . After performing a normal ozone treatment d with a flow rate of about 0.1 to 3.0 m ³ / hr, the adhesive resin layer 5 is hot melt extruded between at least the barrier layer 3 and the inner surface sealant layer 4. Further, the adhesive resin can be laminated in a state where the adhesive strength is stabilized.

In the method for manufacturing a liquid paper container according to the present invention, the corona treatment d applied to at least the surfaces of the barrier layer 3 and the inner surface sealant layer 4 that are in contact with the adhesive resin layer 5 is mainly the adhesive property of the barrier layer 3. After the surface in contact with the resin layer 5 is subjected to a normal corona treatment d of about 50 to 500 BTO / m ² , the adhesive resin layer 5 is hot melt extruded between at least the barrier layer 3 and the inner surface sealant layer 4. And it can laminate | stack in the state which stabilized the adhesive strength of adhesive resin.

  FIG. 1 is a cross-sectional explanatory view of a paper lamination material of a liquid paper container in Embodiment 1 of the present invention.

That is, the surface resin layer 6 of polyethylene (PE) having heat-fusibility and water resistance is heat-melted and extruded on the surface into a film of 20 μm and laminated (called extrusion coating). An outer paper layer 2 of a high-quality liquid paper of 350 g / m ² having excellent properties, and a barrier layer 3 of 12 μm polyester (PET) with ceramic vapor deposition e (SiO _x , 400 nm) having various barrier properties; A 60 μm low density polyethylene (LDPE) inner surface sealant layer 4 having excellent heat fusion and sealing properties;
As shown in FIG. 1, first, a corona treatment d that stabilizes the adhesive strength of the adhesive resin is performed between the barrier layer 3 and the inner surface sealant layer 4, particularly the surface of the barrier layer 3 that contacts the adhesive resin layer 5. After that, the adhesive resin layer 5 of an ethylene-methacrylic acid copolymer (EMAA; AN4228C, manufactured by Mitsui DuPont Co., Ltd.) excellent in heat-fusibility and heat-adhesiveness was melted by heat to form a film having a thickness of 20 μm. Then, the same corona treatment d as described above is applied to the surface between the outer paper material layer 2 and the barrier layer 3 in contact with the adhesive resin layer 5 respectively. In particular, the surface of the ceramic vapor deposition e of the barrier layer 3 is subjected to ozone treatment d that further stabilizes the adhesive strength of the adhesive resin, and then the adhesive resin layer 5 similar to that described above is thermally melted to obtain 30 μm. Film form The paper laminate material of the liquid paper container shown in FIG. 1 was produced by extrusion.

  Next, beautiful printing was performed on the surface of the surface resin layer 6 of the paper sheet material of the liquid paper container shown in FIG. In the punching process, a liquid sheet (not shown) is formed by continuously connecting the top plate group a, a, a, a, the side plate b, b, b, b and the bottom plate group c, c, c, c. After making the container blank, the vertical, horizontal, and height of the container is 70 x 70 x 195 mm while accommodating 1000 ml of orange juice in the same box-making and filling process of the liquid paper container as before. A liquid paper container having a rectangular parallelepiped shape with a gable roof shape on the upper surface shown in 3B was produced.

  Subsequently, the liquid paper container containing the orange juice shown in FIG. 3B of this example was subjected to a storage test for 3 months at 50 ° C., and the paper layered material of the liquid paper container shown in FIG. 3 and the inner surface sealant layer 4 after being stored for 3 months, the adhesive strength is 3.0 N / 15 mm width with no deterioration over time, and the adhesive strength of the conventional urethane adhesive layer 7 Compared to the 2.0N / 15mm width, the adhesive component of the conventional urethane adhesive layer 7 does not elute, so the taste of orange juice stored and stored for 3 months is impaired. We were able to obtain a liquid paper container without fear.

It is sectional explanatory drawing of the paper lamination | stacking material of a liquid paper container in Example 1 of this invention. 2A and 2B are cross-sectional explanatory views of a conventional paper lamination material of a liquid paper container. 3A and 3B are perspective views of a conventional liquid sheet container having a rectangular parallelepiped shape with a flat upper surface or a gable roof shape.

Explanation of symbols

DESCRIPTION OF SYMBOLS 2 ... Outer paper material layer 3 ... Barrier layer 4 ... Inner surface sealant layer 5 ... Adhesive resin layer 6 ... Surface resin layer 7 ... Urethane type adhesive layer 8 ... Aluminum foil a ... Upper surface board group b ... Side board c ... Bottom Face plate group d ... Ozone treatment, corona treatment e ... Ceramic vapor deposition

Claims (2)

  Top plate group a, a, a, a, side plate b, b, b, b and bottom plate group c made of a paper laminated material in which at least the outer paper material layer 2, the barrier layer 3, and the inner sealant layer 4 are laminated. , c, c, c in a liquid paper container having a flat upper surface or a gabled roof shape on the upper surface, and an adhesive resin between at least the barrier layer 3 and the inner surface sealant layer 4 A liquid paper container, wherein the layer 5 is laminated by hot melt extrusion.   In the liquid paper container in which the adhesive resin layer 5 is laminated by hot melt extrusion between at least the barrier layer 3 and the inner surface sealant layer 4 according to claim 1, at least the barrier layer 3 and the inner surface sealant layer 4. A liquid characterized by laminating the adhesive resin layer 5 by hot-melt extrusion after applying either or both of ozone treatment d and corona treatment d to the surface in contact with the adhesive resin layer 5. A method for manufacturing a paper container.

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