JPH08104340A - Laminate tube container - Google Patents

Abstract

PURPOSE: To provide a laminate tube container that is free from difference in levels on the surface on an overlapping part of a seam. CONSTITUTION: Connecting ends 1 and 2 for forming the trunk of a tube that is made up by rolling up a laminated sheet made up by sticking heat-sealable synthetic resin laminae 4 and 5 to both sides of an intermediate lamina 3 made of metal foil or the like are cut beforehand in a form aslant against the surface, and thereby sloped surfaces (a) and (b) are formed. Then, the sloped surfaces (a) and (b) are stuck together by heat sealing while a tape member is stuck to the inside of the connected part of the laminated sheet.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated tube container in which at least an outer surface of a seam is flat.

[0002]

2. Description of the Related Art Conventionally, as a material for an extruded tube container, as shown in FIG. 3, heat-bonding of polyethylene resin or the like as an inner layer and an outer layer on both sides of an intermediate layer 3 made of a metal foil and having a gas barrier property. A laminated sheet having the synthetic resin layers 4 and 5 formed thereon is used.

Further, when the laminated sheet is wound into a tube container, both ends 1 and 2 of the joint are superposed and directly joined by thermal bonding.

[0004]

However, since both end portions of the joint of the above-mentioned laminated sheet are heat-bonded while being overlapped, the overlapping portion of the joint becomes convex due to the step, and printing is performed on this overlapping portion. However, there was a problem in printability and surface workability.

Since a step is formed on the surface of the joint portion as described above, it is difficult to form a printed layer on the surface after the laminated tube container is manufactured. Conventionally, a laminated sheet preliminarily printed is used. For this reason, there are large manufacturing restrictions, such as the need to specify the position of the laminated sheet by the printed position, and the position alignment when manufacturing the laminated tube container from the printed laminated sheet.

Further, since the end face of the one end 1 is exposed to the outside, it may cause separation between the layers of the laminated sheet from the end face, and the appearance may be bad.

Further, since the outer layer synthetic resin layer 4 and the inner layer synthetic resin layer 5 overlap and are heat-bonded to each other at the joint portion, it is difficult to obtain a strong adhesive strength when the inner layer resin and the outer layer resin are different. There was a constraint that it would be difficult to deal with it unless the same resin was used for the inner and outer layers. Therefore, selection of the synthetic resin of the inner layer according to the contents has been restricted.

The present invention has been made in view of the above conventional problems, and an object of the present invention is to provide a laminated tube container in which a step due to an overlapping portion of a joint is eliminated on an outer surface of a joint portion.

[0009]

In order to achieve the above object, the laminated tube container of the present invention is formed by an intermediate layer made of a metal foil or a plastic film, and an inner layer and an outer layer made of a heat-fusible synthetic resin. When the laminated sheet is wound to form the tube body, both ends of the joint of the laminated sheet are previously cut obliquely with respect to the surface to form an inclined surface, and the inclined surfaces of the both ends of the joint are bonded by heat. It is characterized in that it is integrally joined by.

Further, the laminated tube of the present invention is characterized in that a tape member is attached to the inner surface of the joint portion of the container and the laminated sheet.

[0011]

In the laminated tube container of the present invention, since the inclined surfaces of the both ends of the joint which are formed in advance are superposed on each other and then integrally joined by thermal bonding, there is no step and a joined surface having a smooth surface is obtained. To be Therefore, there is no inconvenience in printability and surface workability, and there is no problem of corrosion of metal foil or appearance and appearance.

Further, since the outer layer and the inner layer of the laminated sheet are integrally bonded to each other through the inclined surfaces, not only when the inner layer resin and the outer layer resin are the same, but also when the inner layer resin and the outer layer resin are different. Strong joining is possible. In particular,
It is effective when the intermediate layer is made of a metal foil or a heat resistant plastic film.

Then, by bonding the tape member to the inner surface of the joint portion of the above-mentioned laminated sheet, a stronger joint can be achieved. In particular, it is effective when the intermediate layer is made of a metal foil or a heat resistant plastic film.

[0014]

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIGS. 1 and 2 show an embodiment of the present invention. FIG. 1 is a cross-sectional view showing a state before joining both end portions of a laminated sheet for forming a tube body portion. FIG. 6 is a cross-sectional view showing a state after the joining.

The laminated tube container of the present invention is shown in FIG.
Similarly to the above, the basic layer structure of the laminated sheet, which is the material thereof, includes an intermediate layer 3 made of an aluminum foil or a plastic film, and inner and outer layers 4, 5 made of a heat-fusible synthetic resin layer. It is a laminated sheet having a different structure.

As the intermediate layer 3, a material having a gas barrier property, such as a metal foil such as an aluminum foil, a metal or metal oxide vapor deposition film, an inorganic material or an inorganic oxide vapor deposition film, and heat fusion, A plastic film having a melting point that does not melt. Specifically, a film of polyethylene terephthalate, stretched nylon, stretched ethylene-vinyl alcohol copolymer or the like is used. Also,
A film of the same type as the outer layer that melts during heat welding, such as a polyethylene film, can be used.

In addition, of the above heat-fusible synthetic resins,
As the outer layers 4 and 5, copolymer polyester having heat fusion property, polyethylene such as low density polyethylene and linear low density polyethylene, polyacrylonitrile, ethylene-vinyl alcohol copolymer and the like are used. In the laminated tube container of the present invention, the resins used for the outer layer and the inner layer do not necessarily have to be the same, and different resins can be used for the inner layer and the outer layer. Depending on the type of contents filled in the tube, it is necessary to use a material that does not adversely affect the contents of the inner layer. For example, polyethylene is used for the outer layer 5 and different resins such as copolyester are used for the inner layer 4. be able to. Of the heat-fusible synthetic resin layers, each of the outer layers 4 and 5 does not have to be a single layer, and may have a multilayer structure in which a plurality of resin layers are laminated.

The laminated sheet used for the laminated tube container of the present invention is constructed as described above, and the joint ends 1 and 2 for forming the body of the tube by winding the laminated sheet are shown in FIG. As shown in the figure, the surface is previously cut obliquely with a cutter or the like to form inclined surfaces a and b. The cutting angle is not particularly limited as long as it is an acute angle, but the smaller the cutting angle is, the larger the areas of the inclined surfaces a and b are, and thus the larger the area to be joined is desirable.

As described above, the inclined surfaces a and b of the adhesive end portions 1 and 2 which are cut obliquely to the surface in advance are overlapped with each other, and then appropriate heat and pressure are applied to join the joint end portions 1 and 2. To do.

Here, the outer layer and the inner layer side end surface of the inclined surface a of the end portion 1 of the laminated sheet are overlapped with the outer layer side and inner layer side end surface of the inclined surface b of the end portion 2, respectively, and they are integrated by heat bonding. (See FIG. 2). Therefore, a joint having no step and a smooth surface can be obtained, and even if the resin of the inner layer and the resin of the outer layer are different, the inner layer and the outer layer are joined to each other to obtain a strong joint. In the laminated tube container of the present invention, as shown in FIG. 2, when the tape member 6 having a width of several mm is attached from the inside to the joint portion of the laminated sheet to reinforce the joint portion, the joint strength is increased. This is a particularly preferred embodiment because it can be further increased. If the bonding strength is high, the laminated tube container of the present invention can be used for any purpose regardless of the type of contents.

By the way, the tape member 6 is preferably a heat-adhesive film which does not use an adhesive or the like because it directly contacts the contents. As shown in FIG. 2, the tape member 6 is composed of three layers 6a, 6b, and 6c. For example, when the inner and outer synthetic resin layers 4 and 5 of the laminated sheet are polyethylene, polyethylene (6a) / polyethylene phthalate is used. A tape member composed of (6b) / polyethylene (6c) can be used. As described above, when the synthetic resin layer 4 of the inner layer of the laminated sheet is not, for example, polyethylene but the inner layer of the laminated sheet is changed, the layers 6a and 6c of the tape member 6 are the same as those of the inner layer even if other resins are used. All you need to do is replace the resin. Of course, the tape member 6
The configuration is not limited to the above, and may be arbitrarily changed depending on the material of the laminated sheet used.

Specific examples will be shown below.

A polyethylene terephthalate film (thickness: 12 μm) having a thickness of 12 μm and a silicon oxide vapor-deposited layer (400 Å) provided on the inside of the intermediate layer with a urethane-based adhesive interposed therebetween, a urethane-based anchor coat layer, Extruded low density polyethylene layer (50μ
The inner layer consisting of m) was laminated.

On the other hand, a urethane-based anchor coat layer is interposed outside the intermediate layer, and a melt extruded low density polyethylene layer (thickness 20 μm) and a white polyethylene film (thickness 1
00 μm), melt extruded low density polyethylene layer (thickness 2
0 μm) and an outer layer composed of an antistatic low-density polyethylene film (thickness 40 μm) were laminated to form a laminated sheet of a tube container.

Next, both ends of the laminated sheet were obliquely cut at an angle of about 40 degrees to form an inclined surface. Then, the inclined surfaces were polymerized, heated from both sides to form a joint, and a tubular body was manufactured.

The surface of the joint portion of this tubular body was smooth and had a beautiful appearance. The tear strength of this joint is 5 kgf / 15 mm, which is sufficient to fill and store the contents.

On the inner surface of the joint portion of the cylindrical body having the above-mentioned structure, a low-density polyethylene film (thickness 20 μm) / polyethylene terephthalate film (thickness 9 μm) / low-density polyethylene film (thickness 20 μm) having a width of 5 mm The tape member 6 was thermocompression bonded into a tubular body.

The tear strength of the joint portion of this tubular body is 10 kg.
It was f / 15 mm.

[0030]

As described above in detail, according to the laminated tube container of the present invention, the inclined surfaces of the joining ends of the laminated sheets which are obliquely cut in advance are superposed and then integrated by heat bonding. Since it is bonded to the joint, there can be obtained a joint having a smooth surface without the step difference of the conventional joint.

In addition, since the outer layer and the inner layer at both ends of the laminated sheet are integrally joined via the inclined surfaces, when the resin of the inner layer and the resin of the outer layer are the same, of course, they are strong even if they are different. Since different joints can be obtained, different resins can be used for the inner layer and the outer layer, for example, by selecting the inner layer resin according to the contents.

Further, in the laminated tube container of the present invention, the joining portion can be reinforced by adhering a tape member on the inner surface to the joining portion of the above laminated sheet, and the joining portion can be made stronger.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a state before joining of both joining ends of a laminated sheet for forming a body of a tube.

FIG. 2 is a cross-sectional view showing a state after joining both joined ends of a laminated sheet for forming a body of a tube.

FIG. 3 is a cross-sectional view of a joint portion of a conventional tube.

[Explanation of symbols]

 1, 2 Joined end portion 3 Intermediate layer 4,5 Heat-fusible synthetic resin layer a, b Sloping surface 6 Tape member

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Claims (2)

[Claims] 1. A laminated tube container in which an intermediate layer made of a metal foil, a plastic film or the like, and a laminated sheet made of an inner layer and an outer layer made of a heat-fusible synthetic resin are wound to form a body of a tube. A laminated tube container, characterized in that both joined ends of a laminated sheet are preliminarily cut obliquely with respect to the surface to form an inclined surface, and the inclined surfaces at both joined ends are integrally joined by thermal bonding. 2. The laminated tube container according to claim 1, wherein a tape member is attached to the inner surface of the joint portion of the laminated sheet.