JP2571404B2 - Paper composite container - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a paper composite container formed by an envelope bonding method, and is particularly configured so that paper, aluminum foil, and the like do not come into contact with the contents at a bonding portion. It relates to a paper composite container.

[Conventional technology]

Conventional laminated materials used for packaging bags, including the body, bottom material, lid material, etc. of containers that contain various liquid foods and drinks, tea leaves, spices, etc., both surface layers are composed of polyolefin resin layers Utilizing the thermal adhesiveness of these polyolefin resin layers, they are formed in containers and packaging bags of various shapes.

However, it has been found that when the conventional laminated material in which both surface layers are composed of a polyolefin resin layer is used as, for example, a container body, a container bottom material, a container lid material, or the like, the following problems occur. That is, when forming a polyolefin resin layer or forming a container or packaging bag with the laminated material, the polyolefin resin undergoes thermal decomposition to generate volatile components such as aliphatic hydrocarbons. As a result of the transfer to the contents stored in the bag, the contents generate a taste and an unpleasant odor. Further, the polyolefin resin layer in the laminated material has a disadvantage that the flavor of the content is lost because the flavor component in the content is easily adsorbed or permeated.

In order to solve the above-mentioned drawbacks of the polyolefin resin layer, there has been proposed a laminated material in which a polyester resin layer having a small amount of volatile substances and a good heat-sealing property with good scent retention is used as an inner layer.

[Problems to be solved by the invention]

However, if both surfaces of the laminated material are formed of a polyester resin layer having heat sealing properties, the cost increases. Further, even when a container is formed by using a laminated material composed of a polyester resin layer having heat sealing properties only in the innermost layer, there is a problem of laminating the laminated materials. That is, the polyolefin resin layer of the laminated material on the inner side and the polyester resin layer of the laminated material on the outer side must be joined, but the adhesion between them is generally not good. In addition, there is a problem that the cut surface of the laminated material is exposed inside the container and comes into contact with the contents. When the content is liquid, it penetrates into the paper in the laminated material, and when the content is an acidic liquid such as fruit juice beverage and the aluminum foil is used in the laminated material, corrosion of the aluminum foil occurs. Therefore, it is conceivable to bend the bonded part of the container so that the cut surface of the laminated material does not contact the contents,
The structure of the container bonding part becomes complicated, and the manufacturing cost increases.

Therefore, an object of the present invention is to provide a paper composite container in which the innermost layer is made of a polyester resin layer having heat sealing properties and the outermost layer is made of a polyolefin resin layer without complicating the structure of the bonded portion. With the goal.

[Means for solving the problem]

In view of the above problems, as a result of diligent research, the present inventor has used a tape having a polyolefin resin layer and a polyester resin layer having heat sealability, and the polyolefin resin layer of the laminated material and the polyolefin resin layer of the tape are in contact with the inside and Discovered that a paper composite container with no exudation or denaturation of the contents can be easily formed by covering the cut surface of the laminated material coming in, and interposing a tape between the laminated materials and heat sealing. Then, the present invention has been made.

That is, the paper composite container of the present invention comprises a laminate in which the innermost layer is a polyester resin layer having heat sealing properties and the outermost layer is a polyolefin resin layer. A tape made of a polyester resin layer having a sealing property is interposed so as to cover the end of the inner laminated material, and the tape is attached so that the polyolefin resin layer of the tape comes to the polyolefin resin layer side of the inner laminated material. It is characterized by.

〔Example〕

FIG. 1 is a sectional view showing a paper composite container according to one embodiment of the present invention.

In the laminated material 1 forming the paper composite container, the innermost layer is a polyester resin layer 11 having heat sealing properties, the outermost layer is a polyolefin resin layer 12, and the intermediate layer is a paper composite base material 13. As the polyester resin having a heat sealing property, a thermoplastic polyester resin having a softening point of about 60 to 240 ° C., preferably polyethylene terephthalate in a low crystalline state (softening point of 80 ° C.) or the like is used. Polyesters in a high crystalline state are generally not preferred because of their high softening points, and polyesters in a low crystalline state or non-crystalline polyesters are preferred.
The polyester resin layer 11 has a function of sealing the laminated material 1 by the heat sealing property and preventing leaching and leakage of the contents, and generally has a heat of 3 to 150 μm. The polyolefin resin layer imparts water resistance or the like to the surface of the laminated material, and polyethylene, polypropylene, or the like can be used, and the thickness is generally about 3 to 150 μm.
As the paper composite base material, a paperboard having a thickness corresponding to the shape and size of the container is used, and an aluminum foil is attached as necessary. The thickness of the paper composite substrate is generally 40 to 1000 μm.

The tape 3 to be attached to the bonding portion 2 of the laminated material 1 is composed of a polyolefin resin layer 31, a base material layer 32, and a polyester resin layer 33 having heat sealing properties. Each of the polyolefin resin layer 31 and the polyester resin layer 33 may be made of the same material as the corresponding layer of the laminate 1. It is preferable that the base material layer 32 has sufficient mechanical strength to hold the bonding of the laminated materials 1 and is as thin as possible so that the bonded part 2 is not too bulky. Therefore, a plastic film such as biaxially stretched polyester, or a metal foil such as an aluminum foil is used alone or in a laminated state, and the thickness is generally 5 to 100 μm.
It is.

When the tape 3 is applied to the laminated material 1, (a) the end (cut surface) of the inner laminated material 1 is covered, and (b) the polyolefin resin layer 31 of the tape 3 faces the polyolefin resin layer 12 of the laminated material 1. Thus, the tape 3 is interposed between the bonding portions 2 of the laminated material 1 and joined by heat sealing. According to one preferred embodiment, as shown in FIG. 1, the end of the inner laminated material 1 is bent into a hook shape, and the tape 3 is laminated so that the laminated material 1 and the polyolefin resin layer of the tape 3 are in contact with each other.
And the remaining portion of the tape is interposed in the bonding section 2. However, in addition to the case shown in FIG. 1, a tape can be interposed in the bonded portion of the laminated material by another method as long as the requirements (a) and (b) are satisfied.

The bonding of the laminated material 1 via the tape 3 is performed by heat sealing. The heat sealing temperature is generally between 80 and 240 ° C.

 The present invention is described in more detail by the following examples.

Example 1 A laminated material was formed so as to have the following configuration in order from the outermost layer.

(1) Polyolefin resin layer having a thickness of 30 μm-"Mirason 16P" (manufactured by Mitsui Petrochemical Industries, Ltd.) (2) Acid-resistant paper weighing 400 g / m ² (3) Ionomer resin layer having a thickness of 15 μm-"Himilan 1652" (Mitsui DuPont Polychemical Co., Ltd.) (4) 9 μm thick aluminum foil (5) 12 μm thick biaxially oriented polyethylene terephthalate film (6) 60 μm thick three-layer co-extruded film (a) ) 30 µm thick ethylene-α-olefin copolymer layer-"Ultzex 2020L" (manufactured by Mitsui Petrochemical Industries, Ltd.) (b) 10 µm thick adhesive polyolefin resin layer-
"Admer AT469C" (manufactured by Mitsui Petrochemical Industries, Ltd.) (c) Linear saturated polyester resin layer having a thickness of 20 μm
"PETG 6763" (manufactured by Eastman Kodak Co., Ltd.) Thus, the innermost layer becomes a polyester resin layer having heat sealing properties.

 On the other hand, a tape was formed to have the following configuration.

(1) Polyolefin resin layer having a thickness of 20 μm-“Mirason 16P” (2) Aluminum foil having a thickness of 20 μm (3) Biaxially stretched polyethylene terephthalate film having a thickness of 12 μm (4) Two layers having the following structure having a thickness of 40 μm Coextrusion coating (a) Adhesive polyolefin resin layer of 20 μm thickness
"Admer AT469C" (manufactured by Mitsui Petrochemical Industries, Ltd.) (b) Linear saturated polyester resin layer having a thickness of 20 μm
[PETG6763] The laminated material was bent into the structure shown in FIG. 1, and the tape was interposed in the bonded portion so that both polyolefin resin layers were in contact with each other and so as to cover the end of the inner laminated material. Heat sealing was performed at a surface temperature of 160 ° C. The bonding strength of the paper composite container thus obtained was 3.0 kg / m ^2.
, And even when the liquid was stored, no seepage of the contents into the paper layer was observed.

〔The invention's effect〕

As described above, the paper composite container of the present invention is made of a laminated material having a polyester resin layer having heat sealability on the inside, and a tape configured so that the polyolefin resin layers and the polyester resin layers are adhered to each other at the bonded portion. , The strength of the bonded portion is large. In addition, since the cut surface of the end of the laminated material is covered so as not to be exposed, it is possible not only to prevent denaturation of the content and the like, but also to effectively prevent the liquid content from penetrating into the laminate. .

Further, since the conventional polyolefin resin is used for the outermost layer of the paper composite container having the envelope attached portion at the time of formation, there is no need to change the ink or the like when performing offset printing on the outermost layer. In addition, the outermost layer is also a polyester resin layer having heat sealing properties, and it is better to stick the tape on the envelope sticking part, the amount of polyester resin used is less, and there is also less change in conventional molding, processing, printing method etc. Cost can be reduced.

The present invention can be applied to a brick-type paper composite container, a gobel-top type paper composite container, a tubular paper composite container, and the like.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a paper composite container according to one embodiment of the present invention. DESCRIPTION OF SYMBOLS 1 ... Laminated material 11 ... Polyester resin layer 12 ... Polyolefin resin layer 13 ... Paper composite base material 2 ... Lamination part 3 ... Tape 31 ... Polyolefin resin layer 32 ... Base layer 33 ... Polyester Resin layer

Claims (1)

(57) [Claims] 1. A paper composite container comprising a laminated material in which the innermost layer is a polyester resin layer having heat sealing properties and the outermost layer is a polyolefin resin layer, wherein the laminated material has a polyolefin resin layer / substrate / heat A tape made of a polyester resin layer having a sealing property is interposed so as to cover the end of the inner laminated material in the bonded portion, and the polyolefin resin layer side of the tape comes to the polyolefin resin layer side of the inner laminated material. A paper composite container characterized by being bonded together as described above.