JPH1053243A - Paper-made container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a paper-made container for liq. with small decrease in barrier properties and being easily disposed when a ruled line for forming the container is provided and forming is performed by bending it from the ruled line by using a specified inorg. compd.-deposited film as a barrier material instead of an aluminum foil. SOLUTION: A laminated material prepd. by providing successively a thermoplastic resin layer 1, a paper layer 2, a thermoplastic resin layer 3, a barrier material 8 consisting of an ethylene-vinyl alcohol copolymer layer 4 and an inorg. compd. such as silicon oxide-deposited film and a thermoplastic resin layer 6, is punched into a specified shape and is bent along ruled lines to form a paper container for liq. In addition, the ethylene-vinyl alcohol copolymer layer 4 and the inorg. compd.-deposited film 5 and the inorg. compd.-deposited film 5 and the thermoplastic resin layer 6 are respectively laminated through an adhesive layer such as a urethane adhesive. It is possible thereby to prevent cracks from being generated and barrier properties from being decreased and to store the content stably and for a long time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid paper container using a paper layer as a base material, and more particularly to a liquid paper container using an inorganic compound vapor-deposited film as a barrier material instead of aluminum foil.

[0002]

2. Description of the Related Art Generally, a paper container for storing contents for a long period of 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. ing. On the other hand, paper containers made of a laminated material using an aluminum foil as a barrier material are difficult to separate when recycling the containers, or remain burned during incineration, and have been required to be improved.

Therefore, as a barrier material replacing aluminum foil, a paper container using a vapor-deposited film on which an inorganic compound such as silicon oxide is vapor-deposited has been proposed and put into practical use. However, this inorganic compound vapor-deposited film has a lower barrier property than aluminum foil, and when formed into a paper container, if a ruled line is provided or bent from the ruled line, the vapor-deposited layer is cracked, and the barrier property is further increased. Had declined.

[0004]

Accordingly, the present invention provides a liquid paper container using an inorganic compound vapor-deposited film as a barrier material, and provides a ruled line for molding as a container or bends from the ruled line. It is another object of the present invention to provide a liquid paper container in which the barrier property of the container is small.

[0005]

According to the present invention, there is provided a barrier comprising a paper layer as a substrate, and a vapor-deposited film having an ethylene-vinyl alcohol copolymer layer and an inorganic compound vapor-deposited layer formed inside the substrate in this order. This is a paper container formed by molding a laminated material provided with a layer and a heat seal layer into a predetermined shape. A second invention is a liquid paper container in which a coating layer containing a water-soluble polymer and a metal alkoxide or a hydrolyzate thereof is provided on the surface of the inorganic compound vapor-deposited layer of the vapor-deposited film. A third invention is a liquid paper container provided with a coating layer containing a water-soluble polymer and tin chloride on a surface of an inorganic compound vapor-deposited layer of the vapor-deposited film.

A fourth invention is a liquid paper container having a roof shape or a brick shape in which the laminated material is bent from a ruled line provided in advance and formed. A fifth invention is a liquid paper container in which the laminated material has a cup shape. The sixth invention is
A liquid paper container, wherein the laminated material is a cylindrical sealed container.

[0007]

[Effect] As a barrier material, ethylene-
A vinyl alcohol copolymer layer was provided, and a vapor-deposited film having an inorganic compound vapor-deposited layer formed at a position close to the contents, or a coating layer was provided on the vapor-deposited surface of the vapor-deposited film. Even if cracks occur in the deposited layer due to the formation of and bending from the ruled line, the ethylene-vinyl alcohol copolymer layer on the outer side
It is possible to reduce a decrease in barrier properties.

[0008] Further, since the vapor deposition film having the inorganic compound vapor deposition layer formed inside is disposed, the ethylene-vinyl alcohol copolymer layer can prevent the contents, especially the barrier property from being lowered by the influence of moisture. And high barrier properties can be maintained.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, a thermoplastic resin layer 1, a paper layer 2, a thermoplastic resin layer 3, an ethylene-
A barrier material 8 comprising a vinyl alcohol copolymer layer 4 and an inorganic compound deposited film 5 such as silicon oxide, and a laminated material provided with a thermoplastic resin layer 6 in that order were punched into a predetermined shape to form a blank having ruled lines. Liquid paper container. Although not shown, the ethylene-vinyl alcohol copolymer layer 4 and the inorganic compound vapor-deposited film 5 and the inorganic compound vapor-deposited film 5 and the thermoplastic resin layer 6 are laminated via an adhesive layer such as a urethane-based adhesive. did.

Here, the coating layer 9 is specifically made of polyvinyl alcohol, polyvinylpyrrolidone, sodium alginate and the like. 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 the components lacking furniture can be added to the coating agent alone or in combination of some, and as long as the barrier property of the coating agent is not impaired, an isocyanate compound, a silane coupling agent, or a dispersant may be added. it can.

The liquid paper container is a container which is folded and sealed from a ruled line provided like a roof type container 11 as shown in FIG. 2 or a brick type container 12 as shown in FIG.
In addition, as shown in FIG. 4, a cup-shaped container 13 or, as shown in FIG. 5, a sealed container 14 in which the upper and lower portions of a cylindrical container body are sealed with different members.

As a laminated material usable for the liquid paper container, as shown in FIG. 6, a material in which a coating layer 9 is provided on a vapor-deposited surface of an inorganic compound vapor-deposited film 5 on a barrier material 8 shown in FIG. In addition, 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 vapor deposition surface of the vapor deposition film 5 may be located on either side, but in the case of a highly permeable content, it is better to position the vapor deposition surface on the content side to achieve a lamination by penetration of the content. A decrease in strength can be prevented.

Next, a specific example of the present invention will be described.
As the 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) / ethylene {vinyl alcohol copolymer layer (thickness 15 μm) / 400}
A 1800 ml liquid paper container was manufactured using a material obtained by laminating a polyethylene terephthalate film (12 μm) / low-density polyethylene layer (thickness: 60 μm) in which a silicon oxide vapor-deposited layer was formed in this order. (Example 1) For comparison, 1800 ml of liquid paper was prepared using the same laminated material as in Example 1 except that the ethylene-vinyl alcohol copolymer layer (thickness 15 μm) of Example 1 was not provided. A container was manufactured. (Comparative Example 1) The oxygen permeability of each container of Example 1 and Comparative Example 1 was measured. The results are as follows. Example 1 0.006 ml / day Comparative Example 1 0.06〃

[0014]

According to the present invention, as a barrier material,
Since the ethylene-vinyl alcohol copolymer layer was located near the paper layer and the deposited film was located on the content side,
In each case, the problem of cracks generated at the time of molding the container and the problem of reduced barrier property during storage of the contents can be solved, and the contents can be stably stored for a long period of time.

[0015] As a result, even if the content requires the aluminum foil as the barrier material in the past, it can sufficiently cope with the content, and the use range of the paper container has been widened.

[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 an explanatory view showing another container shape of the present invention.

FIG. 6 is a sectional view showing another laminated material used for the liquid paper container of the present invention.

[Explanation of symbols]

 1, 3, 6: thermoplastic resin layer 2: paper layer 4: ethylene-vinyl alcohol copolymer layer 5: vapor-deposited film 8: barrier material 9: coating layer

Claims (6)

[Claims] 1. A barrier layer comprising a paper layer as a base material, and a vapor-deposited film having an ethylene-vinyl alcohol copolymer layer and an inorganic compound vapor-deposited layer formed on the inner side of the base material in this order;
A paper container formed by molding a laminated material provided with a heat seal layer into a predetermined shape. 2. The liquid paper container according to claim 1, wherein a coating layer containing a water-soluble polymer and a metal alkoxide or a hydrolyzate thereof is provided on the surface of the barrier material on which the inorganic compound is deposited. 3. The liquid paper container according to claim 1, wherein a coating layer containing a water-soluble polymer and tin chloride is provided on the surface of the inorganic compound evaporation layer of the barrier material. 4. The liquid paper container according to claim 1, wherein the container has a roof shape or a brick shape formed by bending and forming a laminated material from a ruled line provided in advance. 5. The liquid paper container according to claim 1, wherein the container has a cup shape. 6. The container according to claim 1, wherein the container is a cylindrical sealed container.
A liquid paper container according to any one of claims 3 to 3.