JPH10167257A - Paper container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sufficient laminate strength for a barrier film on which a paper layer and a vapor deposition layer of a metal, etc., are provided, and in addition, prevent a resin from protruding from the end even when being molded and sealed, and improve the appearance and the performance by using a laminated material for which a processing layer is provided, on the opposite side from the deposited layer of the barrier film. SOLUTION: For a laminated material which is used for this container, from the outside, a thermoplastic resin layer 1, a paper layer 2, a melting polyethylene layer 3, a processing layer 4, a barrier film 5 for which a vapor deposition layer 8 of a metal or a metallic oxide of such as a silicon oxide, etc., and a thermoplastic resin layer 6 are provided in order. Then, the processing layer 4 comprises a polyethylene-imine layer or a urethane resin layer. Thus, the base material for which the paper layer 2 and the barrier film 5 are laminated with the fused polyethylene layer 3 only, can make the resin layer as thin as possible, and for this reason, even when a laminated material using this laminated base material, is molded or sealed, there is no fear that the fused polyethylene layer protrudes.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper container in which a laminated material is formed and sealed, using a barrier film provided with a paper layer and a metal or metal oxide deposited layer as a base material.

[0002]

2. Description of the Related Art Generally, a paper container for preserving contents for a long time is a container formed by molding a laminated material using a paper layer as a base material and aluminum foil as a barrier material into a predetermined shape. Have been. On the other hand, paper containers made of laminated materials using aluminum foil as a barrier material are difficult to separate at the time of recycling of containers, or burnt out at the time of incineration. I was

[0003] In view of this, a paper container using a barrier film provided with a deposited layer of a metal oxide such as silicon oxide has been proposed as a barrier material instead of an aluminum foil, and has been put into practical use. However, as shown in FIG. 6, when the barrier film 5 is laminated via the paper layer 2 and the molten polyethylene layer 3, the barrier film 5 is once on the opposite side of the vapor deposition layer 8 of the barrier film 5 to the same type as the molten polyethylene layer 3. Unless the resin layer 10 was provided, a laminated material having a certain lamination strength via the molten polyethylene layer 3 could not be obtained.

On the other hand, as described above, the vapor deposition film 5
And a paper layer 2 and a molten polyethylene layer 3
When laminating through the resin layer, the total thickness of the resin layer 10 and the molten polyethylene layer 3 becomes a laminated material interposed between the paper layer 2 and the barrier film 5. This laminated material is used as a container 20 having a roof shape, a container 21 having a cup shape, and a container 2 having a cylindrical shape as shown in FIG. 2, FIG. 3 or FIG.
When molded into 2, the resin layer between the paper layer 2 and the barrier film 5 may protrude from the hermetically sealed end, resulting in poor appearance and reduced commercial value.

[0005]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to improve the lamination of a paper layer and a barrier film provided with a metal or metal oxide vapor deposition layer so that the lamination strength is sufficient and the molding, An object of the present invention is to provide a paper container excellent in appearance and performance in which resin does not protrude from an end portion even when hermetically sealed.

[0006]

According to the present invention, a paper layer is made of metal,
Or a barrier film provided with a metal oxide deposition layer, of a substrate laminated with a molten polyethylene layer,
A laminated material provided with a thermoplastic resin layer on at least both sides,
A paper container characterized by using a laminated material provided with a treatment layer on the side opposite to the vapor deposition layer of the barrier film in a container formed and sealed. A second invention is a paper container in which the treatment layer is a polyethylene imine layer or a urethane resin layer. The third, fourth, and fifth inventions are paper containers having a roof shape, a cup shape, or a cylindrical shape obtained by bending and forming the laminated material from a ruled line provided in advance.

[0007]

Since the paper layer and the barrier film are made of a laminated material using a substrate laminated only through a molten polyethylene layer, the resin layer can be made as thin as possible. Form the laminated material used,
Even if hermetically sealed, the molten polyethylene layer does not protrude.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, a thermoplastic resin layer 1, a paper layer 2, a molten polyethylene layer 3, a treatment layer 4, a metal or a vapor deposited layer 8 of a metal oxide such as silicon oxide is formed from the outside. This is a paper container in which a laminated material provided with the provided barrier film 5 and the thermoplastic resin layer 6 in that order is punched into a predetermined shape to form a blank formed with ruled lines.

This liquid paper container is a container which is folded from a ruled line provided like a roof-shaped container 20 and sealed as shown in FIG. In addition, as shown in FIG. 3, a cup-shaped container 21 or, as shown in FIG. 4, a paper container 22 in which the upper and lower portions of a cylindrical container body are sealed with different members.

As a barrier film of a laminated material that can be used for the liquid paper container, as shown in FIG. 5, the vapor deposition layer of the barrier film 5 provided with the metal or metal oxide vapor deposition layer 8 shown in FIG. By using a material in which the coating layer 9 is provided on the eight surfaces, the barrier properties can be further improved. The coating layer 9 is made of either a composition containing a water-soluble polymer and a metal alkoxide or a hydrolyzate thereof, or a composition containing a water-soluble polymer and tin chloride. Here, the surface of the vapor deposition layer 8 of the barrier film 5 may be located on either side, but is preferably located on the content side,
The penetration of the contents can be further prevented.

Here, specific examples of the water-soluble polymer used for the coating layer 9 include polyvinyl alcohol, polyvinyl pyrrolidone, and sodium alginate.
In particular, when polyvinyl alcohol is used, gas barrier properties are excellent. The tin chloride may be stannous chloride, stannic chloride, or a mixture thereof, and may be an anhydride or a hydrate. Further, as the metal alkoxide, tetraethoxysilane, triisopropoxyaluminum, or a hydrolyzate thereof can be used. And each of the above components can be added to the coating agent alone or in combination of several,
An isocyanate compound, a silane coupling agent, a dispersant, or the like can be added as long as the barrier property of the coating agent is not impaired.

The thermoplastic resin layers 1 and 6 can be used as long as they have a heat-sealing property. Specific examples include low-density polyethylene, linear low-density polyethylene, polyethylene polymerized with a metallocene catalyst, and polypropylene. Or a resin in which these are mixed can be used. As the thermoplastic resin layer 6 serving as the inner layer 6, when heat resistance is required, polypropylene or a mixed resin using polypropylene, and when emphasis is placed on fragrance, polyethylene polymerized with a metallocene catalyst, or mixing using this resin A resin may be used.

Next, a specific example of the present invention will be described. (Example 1) As a laminated material used, from the outside, a low-density polyethylene layer (thickness: 25 μm) / paper layer (basis weight: 320)
g / m ² ) / low density polyethylene layer (thickness 30 μm) /
Polyethylene imine layer (thickness: 3.5 g / m ² ) / 400
Using a material laminated in order of a polyethylene terephthalate film (12 μm) / low-density polyethylene layer (thickness 60 μm) on which an aluminum oxide vapor-deposited layer was formed as shown in FIG.
The liquid paper container of the roof type shape of 1000 ml shown in (1) was manufactured.

Comparative Example 1 For comparison with Example 1, a polyethylene layer (thickness: 15 μm) was provided instead of the polyethylene imine layer of Example 1 above.
Using the same laminated material as in Example 1, a 1800 ml roof-shaped liquid paper container was manufactured.

A comparison of the state of the upper end portions of the containers of Example 1 and Comparative Example 1 which were sealed under heat and pressure was as follows.
In Example 1, the resin did not protrude from the end, but in Comparative Example 1, the resin protruded from the end.

(Example 2) As a laminated material used, from the outside, a low density polyethylene layer (thickness: 25 μm) / paper layer (basis weight: 280 g / m ² ) / low density polyethylene layer (thickness: 30 μm) / polyethyleneimine Layer (thickness 3.5 g / m
² ) Using a material laminated in order of a polyethylene terephthalate film (12 μm) / low density polyethylene layer (thickness 50 μm) on which a silicon oxide vapor deposition layer of / 400 ° was formed,
A 250 ml cylindrical liquid paper container shown in FIG. 4 was manufactured.

Comparative Example 2 For comparison, a laminated material similar to that of Example 1 except that a polyethylene layer (thickness: 15 μm) was provided instead of the polyethylene imine layer of Example 1 described above. Was used to produce a 250 ml cylindrical liquid paper container. Comparison of the state of the sealed end of each container of Example 1 and Comparative Example 1

In Example 2, the resin did not protrude from the end of the crimped portion, but in Comparative Example 2, the resin protruded from the end of the crimped portion.

[0019]

As described above, according to the present invention, since the vapor-deposited film and the paper layer are laminated by the molten polyethylene layer having the minimum thickness, the sealing or bending by heating and pressing can be carried out. The polyethylene layer did not protrude from the end, and a container having an excellent appearance could be obtained.

In addition, even if the layers are laminated via a molten polyethylene layer, since a treatment layer is previously applied to the film surface of the vapor-deposited film, sufficient adhesive strength can be secured and the performance of the container is reduced. There is no.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a laminated material used for a liquid paper container of the present invention.

FIG. 2 is an explanatory view showing a container shape of the present invention.

FIG. 3 is an explanatory view showing another container shape of the present invention.

FIG. 4 is an explanatory view showing another container shape of the present invention.

FIG. 5 is a sectional view showing another laminated material used for the liquid paper container of the present invention.

FIG. 6 is a sectional view showing a laminated material used in a conventional liquid paper container.

[Explanation of symbols]

 1, 6 ... thermoplastic resin layer 3 ... molten polyethylene layer 2 ... paper layer 4 ... treatment layer 5 ... barrier film 8 ... vapor deposition layer 9 ... coating layer 20 ... roof-shaped container 21 ... cup-shaped container 22 ... cylinder Mold shaped container

Claims (5)

[Claims] 1. A laminated material having a thermoplastic resin layer provided on at least both sides of a base material obtained by laminating a paper layer with a barrier film provided with a metal or metal oxide deposited layer by a molten polyethylene layer, is formed. A paper container characterized by using a laminated material provided with a treatment layer on the side opposite to the vapor deposition layer of the barrier film in a sealed container. 2. The paper container according to claim 1, wherein the treatment layer comprises a polyethylene imine layer or a urethane resin layer. 3. The paper container according to claim 1, wherein the container has a roof shape or a brick shape obtained by bending and forming a laminated material from a ruled line provided in advance. 4. The paper container according to claim 1, wherein the container has a cup shape. 5. The paper container according to claim 1, wherein the container is a cylindrically sealed container.