JPH0740959A - Composite container - Google Patents

Abstract

PURPOSE:To provide a composite container which is equipped with an excellent barrier property, of which the incineration after usage is easy, and which can be used in a microwave oven by a method wherein a thermoplastic resin in injected into a die, and integrated with a blank sheet with a barrier property which is previously arranged in the die. CONSTITUTION:A blank sheet 3 equipped with a barrier layer comprising a resin film and an inorganic deposited film on a resin film is arranged between a core and female die of an injection-molding die previously, and a thermoplastic resin in injected. By doing so, a pillar part 4, flange part 5, shoulder part 10 and a mouth part 11 are formed. At this time, the blank sheet 3 whose shape is maintained a cylindrically is integrated by fusing with the thermoplastic resin constituting the pillar part 4, flange part 5, and shoulder part 10 respectively, at the end parts, a lower open end 3b and upper open end 3c. For a bottom part 6 also, a blank sheet 8 for the bottom part is previously arranged in the injection-molding die, and a flange part 7 can be integrally formed on the periphery of the blank sheet 8 by injecting the thermoplastic resin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite container having advantages such as molding accuracy, strength and processing characteristics as an injection molded product, printing effect as a paper container, and lightness.
The present invention relates to a composite container which has a particularly excellent barrier property and can stably store any contents such as powder and liquid and which can be easily incinerated after use.

[0002]

2. Description of the Related Art Conventionally, a so-called pillar container in which a blank plate and a thermoplastic resin are integrally molded is used.

Generally, in a pillared container, a blank plate made of a laminated sheet material in which paper and a resin are laminated is arranged in a cylindrical shape in an injection molding die, and the end portion of the blank plate is abutted with each other. In addition, the blank container is a composite container integrally molded in a state where the blank plate is held in a container shape by a holding frame made of resin by injecting a thermoplastic resin into the open end and the like. Here, the blank plate generally has a laminated structure including a barrier layer made of aluminum foil and a thermoplastic resin layer positioned on the innermost surface. Then, the injected thermoplastic resin and the thermoplastic resin layer on the innermost surface are fused by heat to be integrated into a composite container, and the strength of the molded composite container is high.

Such a pillar container has both advantages as an injection molded product and as a paper container, and also has a barrier property. For example, soft drinks, sake, powder detergent, fragrance, liquid foods, etc. It is widely used as a container for various products.

[0005]

However, in the conventional composite container, the aluminum foil is used as the barrier layer in the blank plate, so that although a stable oxygen barrier property is obtained, the suitability for incineration is poor and the waste after use is discarded. There was a problem that disposal was not easy. Further, the conventional composite container has a problem that it cannot be used in a microwave oven because the blank plate has an aluminum foil.

The present invention has been made in view of such circumstances, and provides a composite container which has an excellent barrier property, is easy to incinerate after use, and can be used in a microwave oven. The purpose is to do.

[0007]

To achieve these objects, the present invention comprises a body, a bottom, and an upper closure.
A blank plate having a barrier property and a thermoplastic resin injected into an injection molding die in which the blank plate is arranged in advance are integrally molded, and the blank plate is formed on a resin film. The structure was such that a barrier layer formed with an inorganic vapor deposition film was provided.

[0008]

[Function] A blank plate constituting a composite container is provided with a barrier layer in which an inorganic vapor deposition film is formed on a resin film, and a thermoplastic resin is injected into an injection molding die in which the blank plate is arranged in advance to be integrated with the blank plate. The composite container has excellent barrier properties, and has high incineration suitability because it does not use a metal foil for the blank plate, and suitability for use in a microwave oven.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing an example of the composite container of the present invention, and FIG. 2 is a sectional view taken along line II-II of the composite container shown in FIG. In FIGS. 1 and 2, the composite container 1 is a so-called pillar container including a body portion 2, a bottom portion 6, and an upper closing portion 9.

The body portion 2 of the composite container 1 is formed by injecting a thermoplastic resin into a blank plate 3 held in a tubular shape and a joint portion where the ends 3a of the blank plate 3 are butted against each other. A pillar portion 4 and a flange portion 5 formed by injecting a thermoplastic resin at the lower open end 3b of the blank plate 3 held in a tubular shape are provided.

The bottom portion 6 is composed of a flange portion 7 formed of a thermoplastic resin around a blank plate 8 for the bottom portion, and is formed separately from the body portion 2. The flange portion 7 is integrated with the body portion 2 by being fixed to the inner peripheral surface of the flange portion 5 of the body portion 2. The flange portion 7 and the inner peripheral surface of the flange portion 5 may be fixed to each other by forming a screw portion and screwing them together, or by various methods such as a heat sealing method and an ultrasonic sealing method.

Further, the upper closed portion 9 comprises a shoulder portion 10 and a threaded opening portion 11 projecting from the shoulder portion 10 substantially at the center thereof. The upper closing portion 9 is formed integrally with the body portion 2 and is located above the open end 3c of the blank plate 3 held in a tubular shape.
It is formed by injecting a thermoplastic resin. And
A cap, a cap with a pump (shown by an imaginary line in FIG. 1) or the like is screwed into the threaded opening 11 to seal the inside of the composite container 1.

The composite container 1 as described above has a blank plate 3
Is disposed in advance between the core of the injection molding die and the female die, and then the thermoplastic resin is injected, whereby the pillar portion 4, the flange portion 5, the shoulder portion 10 and the threaded opening are formed. The part 11 is molded, and at this time, the blank plate 3 held in a cylindrical shape has the pillar part 4, the flange part 5, and the shoulder part at the ends 3a, 3a, the lower open end 3b, and the upper open end 3c, respectively. The thermoplastic resin forming 10 is fused and integrated. At this time, it is preferable that the blank plate 3 be wound around the core in advance and be folded in a curl. Also, the bottom 6
Also, the blank plate 8 for the bottom portion is previously arranged in the injection molding die, and then the thermoplastic resin is injected to produce the blank plate 8
It is possible to integrally form the flange portion 7 around the periphery with a thermoplastic resin.

The appearance of the pillar portion 4 formed by injection of the thermoplastic resin is not easily confirmed from the outside of the composite container 1 because it is preferable from the appearance. Therefore, the amount of resin in the pillar portion 4 should be as small as possible. It is preferable to reduce the amount. Also,
As shown in FIG. 2, ribs 4 are provided inside the container of the pillar portion 4.
You may project a. By thus projecting the ribs 4a, stacking between the body parts is prevented when the body parts 2 before the bottom part 6 are integrated are stacked and stored or transported, and the subsequent separation is easy. Becomes

As described above, the blank plate 3 and the blank plate 8
Polyethylene resin, polypropylene resin, polystyrene resin, polybutylene terephthalate resin, polyethylene terephthalate resin, polyacrylonitrile resin and polyamide resin represented by the following chemical formula are used as the thermoplastic resin which is integrated with can do.

[0016]

[Chemical 1] The thermoplastic resin as described above is preferably a thermoplastic resin of the same type as the thermoplastic resin layer forming the innermost surface of the blank plate 3.

The blank plate 3 is not particularly limited as long as it is a laminate having at least a paper layer, a barrier layer, and an innermost surface layer made of a thermoplastic resin in order from the outside of the composite container 1.
For example, an outermost surface layer made of a thermoplastic resin may be provided outside the paper layer.

As a concrete example of the blank plate 3, for example, FIG.
A blank plate as shown in can be mentioned. In FIG. 3, the blank plate 3 is a barrier adhered to the paper 22 via the thermoplastic resin layer (outermost surface layer) 21, the paper 22, and the adhesive resin layer 23 in this order from the side forming the outer wall surface of the composite container 1. Layer 24 and thermoplastic resin layer (innermost layer) 25
It has a laminated structure of.

Thermoplastic resin layer 2 constituting the blank plate 3
As the materials 1 and 25, the thermoplastic resins mentioned above as the thermoplastic resins that are integrated with the blank plate 3 and the blank plate 8 to form the composite container 1 can be used.
The thermoplastic resin layers 21 and 25 may be made of the same thermoplastic resin or different thermoplastic resins, but the thermoplastic resin layer 25 constituting the innermost surface is the blank plate 3, It is preferable that the thermoplastic resin is of the same type as the thermoplastic resin that is integrated with the blank plate 8 to form the composite container 1. The thickness of such a thermoplastic resin layer 21 is 1
0 to 40 μm, the thickness of the thermoplastic resin layer 25 is 20 to
It is preferably about 80 μm.

The paper 22 constituting the blank plate 3 preferably has a basis weight of about 200 to 400 g / m ² . The barrier layer 24 is formed by depositing the inorganic vapor deposition film 24a on the resin film 24b.
Is formed. The resin film 24b used is preferably a biaxially stretched resin film, and specifically, a resin such as polyester resin, polyamide resin, polycarbonate resin, acrylic resin, polyvinyl alcohol resin, ethylene / vinyl alcohol copolymer, polystyrene resin, or the like. A biaxially stretched film can be used. In particular, a film obtained by biaxially stretching a heat resistant resin such as a polybutylene terephthalate resin, a polyethylene terephthalate resin, a polyacrylonitrile resin and a polyamide resin represented by the following chemical formula is preferable.

[0021]

[Chemical 2] The thickness of such a resin film 24b is about 5 to 30 μm, preferably about 10 to 20 μm.

Inorganic vapor deposition formed on the above resin film
The film 24a is made of silicon dioxide (SiO2). ₂) Etc. silicon oxide
Thing (SiO_x) Is a vapor deposition film. This silicon oxide (S
iO _xThe method for forming the vapor deposition film in
Vacuum deposition methods such as the electron beam method and electron beam method are preferably adopted.
It

The thickness of such an inorganic vapor deposition film 24a is 1
Is about 1000 nm, preferably about 50 to 100 nm. If the thickness of the inorganic vapor-deposited film is less than 10 nm, the gas barrier property may not be sufficiently exhibited, and if the thickness of the inorganic vapor-deposited film exceeds 100 nm, the inorganic vapor-deposited film is likely to be cracked, resulting in gas barrier. This is not preferable because the risk of deterioration of the property is generated and the cost is high.

The adhesive resin layer 23 for adhering the paper 22 and the barrier layer 24 can be formed using, for example, a carboxyl group-containing polyethylene resin. Specific examples of the carboxyl group-containing polyethylene resin include:
Ethylene-acrylic acid copolymer (EAA), ethylene-
Methacrylic acid copolymer (EMAA), ionomer resin, ethylene-maleic anhydride copolymer, ethylene-ethyl acrylate-maleic anhydride copolymer and the like can be mentioned. The thickness of the adhesive resin layer 23 is 15 to 30.
About μm is preferable.

The blank plate 3 may have a structure in which a heat resistant layer is provided between the barrier layer 24 and the thermoplastic resin layer 25. This heat-resistant layer can be formed of a biaxially stretched polyester resin film such as a polyethylene terephthalate film, a polyamide resin film such as a nylon film, a stretched polyolefin resin film such as a polypropylene film, or the like. The thickness of such a heat-resistant layer is preferably about 10 to 30 μm.

The thickness of the blank plate 3 as described above is preferably about 300 to 600 μm. The composite container of the present invention as described above uses, as a blank plate having a barrier property, a blank plate provided with a barrier layer formed by forming an inorganic vapor deposition film on a resin film instead of a barrier layer made of a metal foil such as an aluminum foil. Therefore, while having a barrier property equivalent to that of a conventional composite container, it also has high incineration suitability and suitability for use in a microwave oven.
Furthermore, by using a heat-resistant resin film as the resin film forming the barrier layer, the influence of the pressure and heat of the thermoplastic resin injected in the molding of the composite container is prevented from affecting the paper layer.

Further, the shape of the composite container of the present invention is not limited to the above-mentioned example, but may be various shapes. For example, as shown in FIG. 4, the body forming portion 33
A blank container 32 composed of a and 33b and the upper blocking portion forming portion 34 may be used to form the composite container 31 having the shape shown in FIG. In this composite container 31, a pillar portion 36 made of a thermoplastic resin is formed at the joint portion of the blank plates 32. In addition, an upper closing portion edge portion 38 is formed in an upper closing portion 37 formed by the upper closing portion forming portion 34 of the blank plate 32, and a lower flange portion 39 is formed below the blank plate 32. There is. Then, a threaded opening 40 is fixed to a mouth portion 35 formed in the upper closed portion forming portion 34 of the blank plate 32. The threaded opening 40 may be integrally formed with the pillar portion 36 and the upper closing portion edge portion 38. In addition, a bottom material formed separately from the container is bonded to the lower flange portion 39.

As a means for integrating the body 2 and the bottom 6, the ultrasonic sealing method can be used as described above. In this case, as shown in FIG. 6, the flange 5 of the body 2 is used. A convex portion 5a can be provided on the lower end surface of the. Since such a convex portion 5a is selectively melted by ultrasonic waves, quick and reliable heat sealing can be performed. Also, to prevent the molten resin from flowing out between the flange portion 5 and the bottom portion 6,
An L-shaped edge portion 5b may be provided on the outer edge portion of the flange portion 5 as in the illustrated example. The shape of the convex portion 5a may be any shape such as a ring shape and a protrusion shape such as a cone, and the height of the convex portion 5a is 0.1 to 0.5 mm.
The angle of the top of a is preferably in the range of 60 to 120 °.
Further, the convex portion (5a) may be provided on the bottom portion 6.

Next, the present invention will be described in more detail with reference to experimental examples. (Experimental example) First, acid-resistant paper having a basis weight of 230 g / m ² was used as a support, and a low-density polyethylene resin was extrusion-laminated on one side of the acid-resistant paper to form a thermoplastic resin layer having a thickness of 15 μm, and two layers were laminated. Created the body.

On the other hand, a biaxially stretched polyester film (thickness = 12 μm) having a vapor deposition film (thickness: 50 nm) of silicon oxide (SiO _x ) as a barrier layer and a low density polyethylene resin film (as a thermoplastic resin layer ( A two-layer laminate having a thickness of 45 μm) was formed.

Next, the ethylene-methacrylic acid copolymer (E
MAA) was extruded in a thickness of 15 μm, and the silicon oxide (SiO _x ) vapor deposition film side of the other two-layer laminate was adhered to form a laminate.

Next, this laminate was punched into a predetermined shape to obtain a body blank plate and a bottom blank plate. After that, after loading each blank plate in a predetermined injection mold, injection molding is performed using polyethylene resin, to create a portion consisting of a body portion and an upper closing portion constituting the composite container, and a bottom portion, By ultrasonically sealing both, a composite container (Sample 1) having an internal volume of 720 cm ³ as shown in FIG. 1 was prepared.

For comparison, an aluminum foil (thickness = 9 μm) was used in place of the biaxially stretched polyester film having a silicon oxide (SiO _x ) vapor deposition film as a barrier layer, except that the above composite container (Sample 1) was used. A composite container (Comparative sample 1) for comparison was prepared in the same manner as in (1).

Each composite container (Sample 1,
With respect to the comparative sample 1), the amount of oxygen permeated at room temperature and under normal pressure was measured using Oxytran manufactured by Modern Control. In addition, each composite container was incinerated and the state was observed. The results are shown in Table 1 below.

[0035]

[Table 1] As shown in Table 1, it was confirmed that the composite container of the present invention has a high barrier property, does not leave ash after incineration, and has a good incineration property.

When the composite container of the present invention could be easily heated with water when each composite container was filled with water and used in a microwave oven, aluminum foil was applied to the blank plate. In the composite container (Comparative Sample 1) having the same, the heating efficiency of water was significantly reduced.

[0037]

As described above in detail, according to the present invention, the thermoplastic resin is injected into the injection molding die in which the blank plate having the barrier layer having the inorganic vapor deposition film formed on the resin film is arranged in advance. The composite container has an excellent barrier property, and since it does not use metal foil on the blank plate, it has high incineration suitability and is used in a microwave oven. The effect of having aptitude is exhibited.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of a composite container of the present invention.

2 is a sectional view taken along line II-II of the composite container shown in FIG.

FIG. 3 is a schematic cross-sectional view showing an example of a blank plate used in the composite container shown in FIG.

FIG. 4 is a plan view of a blank plate used in another example of the composite container of the present invention.

FIG. 5 is a perspective view showing another example of the composite container of the present invention.

FIG. 6 is a cross-sectional view showing an example of integration of a body portion and a bottom portion of the composite container of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Composite container 2 ... Body part 3 ... Blank plate 4 ... Pillar part 6 ... Bottom part 9 ... Upper block part 21 ... Thermoplastic resin layer 22 ... Paper 23 ... Adhesive resin layer 24 ... Barrier layer 24a ... Inorganic vapor deposition film 24b ... Resin film 25 ... Thermoplastic resin layer

Front page continuation (72) Inventor Kazuko Yamase 1-1-1, Ichigayaka-cho, Shinjuku-ku, Tokyo Dai Nippon Printing Co., Ltd. Nakayama Industry Co., Ltd.

Claims (2)

[Claims] 1. A blank plate having a barrel portion, a bottom portion, and an upper closing portion and having a barrier property, and a thermoplastic resin injected into an injection molding die in which the blank plate is arranged in advance are integrated. The composite container is characterized in that the blank plate comprises a barrier layer having an inorganic vapor deposition film formed on a resin film. 2. The composite container according to claim 1, wherein the resin film forming the barrier layer is a resin film having heat resistance.