JP2003341752A - Composite container - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composite container which is formed by inserting a blank plate into a mold and integrating them by injection-molding a resin into a skeleton, can safely seal a beverage, food or the like and is both heat-resistant enough to be heated in a microwave oven and so adiabatic that the heated container is not hot when carried in hands. <P>SOLUTION: The blank plate 50 for example is prepared by blanking a laminate sheet having a polypropylene-based resin layer provided on the innermost layer with paper as a base and a layer of a low density polyethylene or its copolymer provided as a foaming layer on the outermost layer. The blank plate 50 is inserted into the mold and injection-molded by using a polypropylene-based resin of the same base as that of the innermost layer as an injection-molding resin. The blank plate 50 and the skeleton resin consisting of a pedestal 7, a bottom coupling resin part 8, a longitudinal frame resin part 6, a rim frame resin part 9 and a flange 10 are integrally molded to make the composite container 100. The container is placed into a heating furnace of approximately 150°C for foaming the resin in the foaming layer. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a composite container,
More specifically, a blank plate obtained by punching out a laminated sheet in which at least paper and a plastic layer are laminated is inserted into a molding die, and a resin is injection-molded to integrally mold the resin and the blank plate. A composite container to be formed, which has heat resistance to withstand heating and cooking of contents such as filled beverages and foods by a microwave oven, and when holding the container with the heated contents by hand. Also, the present invention relates to a composite container having a heat insulating property that can be safely held without being burned.

[0002]

2. Description of the Related Art Conventionally, in a relatively simple form as a heat-insulating container made of paper and plastic, for example, paper is used as an intermediate layer, the inner surface of which is extruded and coated with medium density polyethylene, and the outer surface of which is extruded with low density polyethylene. There is known a paper cup in which a coated laminated sheet is formed into a cup shape and is passed through a heating furnace at about 150 ° C. to foam a low-density polyethylene layer on the outer surface to impart heat insulation. Since a foam layer is formed on the outer surface of such a paper cup,
Even if the contents are hot coffee or other hot things,
It has a heat insulating property that can be safely held.

However, in the paper cup as described above, since the body and the bottom are joined by heat sealing using the medium density polyethylene laminated on the inner surface, the heat resistance is not sufficient, and for example, the paper cup is filled. When the contents are heated or cooked in a microwave oven, the medium density polyethylene softens and the adhesive is peeled off, and the heat generated by the microwave oven tends to burn the paper edge (especially the tail end). There was a problem. In addition, the thermal bonding of the body and bottom of the paper cup is apt to become unstable, so if you do not take special measures, you cannot wipe out the concern about liquid leakage, and you can fill and seal the liquid for circulation. The fact is that there are few examples. In order to improve the heat resistance of the adhesive portion of the paper cup, for example, it is possible to laminate polypropylene having high heat resistance on the inner surface, but when polypropylene is laminated on the inner surface, improvement in heat resistance can be expected, but the adhesion itself There is a problem that it becomes more unstable than when medium density polyethylene is used, and it was practically difficult to use polypropylene.

On the other hand, as a composite container of paper and plastic, for example, in addition to paper and plastic, a blank sheet is prepared by punching out a laminated sheet in which aluminum foil, aluminum vapor-deposited film and the like are laminated, if necessary. Formed to insert into the mold to form a cup-shaped container body, bottom or around the bottom,
There is a composite container that is manufactured by injecting resin in a frame-like shape only into a necessary portion such as a joint portion of a body portion, a pillar portion, and a peripheral edge portion of an upper opening end, and is integrally molded, for example, a composite container called a pillar pack.

In such a composite container, since the joint portion of the blank plate is integrally molded and joined with the injection-molded resin injected in a skeleton shape, sufficient heat and pressure are applied and stable adhesion is achieved. Sex is obtained. Therefore, by using polypropylene, which has excellent heat resistance and water resistance, for the innermost layer of the blank plate and the injection molding resin, for example, the adhesiveness of the joint part of the blank plate can be strongly stabilized and there is no risk of liquid leakage. Moreover, a composite container having excellent heat resistance can be obtained. When the composite container requires gas barrier properties, the gas barrier properties can also be improved by laminating an aluminum foil, an aluminum vapor deposition film, or the like between the blank plate paper and the innermost layer.

[0006]

However, even such a composite container has the advantages as described above,
To improve the gas barrier property, if a vapor deposition film of aluminum foil or metal such as aluminum is laminated on the blank plate, the microwave oven cannot be used to heat the contents, and if the contents are heated, the container is insulated. There was a problem that it was hot and could not be held by hand.

The present invention has been made to solve the above problems, and an object thereof is to form a blank plate by punching out a laminated sheet in which at least paper and a plastic film are laminated. A composite container formed by integrally molding a resin and a blank plate by inserting the resin into a mold and injection-molding the resin, wherein the injection-molded resin and the blank plate have good adhesion and Can be safely sealed and packaged even if it is a liquid content such as various drinks and soups, and it has heat resistance to withstand heating by a microwave oven or hot warmer, and even when the content is heated, A composite container with excellent performance and suitability for use, which has a heat insulation property that is not too hot and can also improve the gas barrier property to improve the storability of contents. It is to provide good production properties.

[0008]

The above-mentioned problems can be solved by the present invention described below. That is, in the invention described in claim 1, a blank plate formed by punching out a laminated sheet in which at least a paper and a plastic layer are laminated is inserted into a molding die, and the resin is injection-molded to obtain the resin and the blank plate. In a composite container formed by integrally molding and, the innermost layer of the blank plate and the injection-molded resin portion are formed of polypropylene resin or polyester resin, and a foam layer of resin is formed on the outer surface of the blank plate. The composite container having heat resistance and heat insulating properties is provided.

In the present invention, the shape of the composite container is not particularly limited. For example, in addition to a round container having a circular or elliptical cross section, a square, rectangular, or polygonal cross section is used. It can be a rectangular container. In order to facilitate handling such as stacking of the composite container, a composite container having a taper is preferable.

For the convenience of manufacturing, the resin foam layer provided on the outer surface of the blank plate is not foamed before injection molding,
It is preferable to heat-foam after molding the container. A foaming agent that generates gas by thermal decomposition can be added to the resin to be heated and foamed, but since paper is used as the base material of the blank plate, its outer surface has a relatively melting point such as low density polyethylene. By providing a resin layer having a low temperature, the air contained in the paper layer expands by heating and the water contained in the paper evaporates even if a foaming agent is not added. It can be foamed.

The paper used for the blank plate is not particularly limited, but in order to reduce the amount of injection molding resin used as much as possible and to give the composite container the necessary rigidity,
It is preferable that the paper itself has an appropriate rigidity, and for that purpose, it is preferable to use paperboard. Specific examples of the paper used for the blank board include cup base paper, ivory paper, card paper, coated balls, etc., and the basis weight of the rice should be selected in the range of 200 to 500 g / m ² according to the container size. Is preferred.

The blank plate has the paper as a base material and has a foamed layer of resin on the outer surface thereof, and at least the inner surface (innermost layer) has a resin of the same type as the injection molding resin, that is, a polypropylene resin. Alternatively, it is preferably formed by providing a layer of polyester resin, whereby moisture resistance, water resistance, content resistance, etc. can be imparted to the blank plate, and at the same time, adhesiveness with the injection molding resin can be strengthened. . Further, the bottom of the composite container may have a shape in which a leg made of injection-molded resin is provided on the outer periphery thereof, or may have a shape having no leg.

By adopting the above-mentioned constitution, the composite container of the present invention is excellent in heat resistance because the innermost layer of the blank plate and the injection-molded resin portion are formed of polypropylene resin or polyester resin. At the same time, both are firmly adhered, even if the contents filled in the container are liquid contents such as various beverages and soups, there is no risk of liquid leakage, and it can be safely sealed and packed, and the microwave oven and It has enough heat resistance to withstand the heat of hot warmers. And, since the foam layer of the resin is provided on the outer surface of the blank plate, heat insulation is imparted to the container, and even when the contents are heated hot in a microwave oven or the like,
The outside of the container is not very hot and can be safely held by hand. In addition, the bottom of the composite container does not have legs (thread tails) due to the folding of the paper as seen at the bottom of a cup-shaped paper cup container. The contents can be safely heated without causing liquid leakage.

The invention according to claim 2 is the composite container according to claim 1, wherein the thickness of the polypropylene resin or polyester resin of the innermost layer of the blank plate is 30 μm or more and 200 μm or less. .

The thickness of the polypropylene resin or polyester resin of the innermost layer is 30 μm or more and 200 μm or more.
It is preferably m or less. The thickness of the resin is 30μ
When it is less than m, for example, when the innermost layer is independently laminated inside the paper of the blank board, pinholes are likely to occur in the innermost layer, which is not preferable. Further, when the thickness of the resin exceeds 200 μm, it is not preferable because the thickness is too thick, the repulsive force of the blank plate increases, and the moldability such as bending decreases. It is also not preferable in that the mass ratio of plastic to paper in the composite container becomes high.
Therefore, by adopting the above structure, in addition to the function and effect of the invention described in claim 1, liquid leakage due to pinholes can be more reliably prevented, and the composite container is also excellent in moldability. Can be

The invention according to claim 3 is characterized in that the foam layer on the outer surface of the blank plate is formed of low-density polyethylene or a copolymer thereof, from the composite container according to claim 1 or 2. Become.

The foam layer is provided to impart heat insulating property to the container, and for that purpose, it may be provided on the outer surface of the blank plate, and when the resin on the inner surface of the blank plate foams, the laminating strength of that portion is obtained. Is deteriorated and the hermeticity may be impaired, which is not preferable. Therefore, it is preferable that the resin of the foam layer basically has a lower melting point or softening point than the resin laminated on the inside of the paper of the blank plate. Further, when it is necessary to use a resin having the same melting point or softening point, it is possible to suppress foaming due to heating by making the thickness of the inner resin larger than that of the foam layer. From the above viewpoint, low-density polyethylene or a copolymer thereof having a relatively low melting point can be preferably used as the resin of the foam layer on the outer side of the blank plate.

Therefore, by adopting the above-mentioned structure, in addition to the effect of the invention described in claim 1 or 2, after molding the composite container, the resin of the foam layer on the outer surface of the blank plate is heated. When foaming the composite container, only the resin in the foamed layer can be more surely foamed, and the composite container having excellent heat insulating properties can be manufactured without impairing the sealing property of the composite container.

The invention according to claim 4 is the composite container according to any one of claims 1 to 3, wherein the blank plate is provided with a vapor deposition layer of an inorganic oxide.

Depending on the contents to be filled in the container, it is necessary to improve the gas barrier property of the composite container in order to improve its storability. In that case, it can be dealt with by providing a gas barrier layer on the blank plate,
In the composite container of the present invention, the heating suitability of the contents in a microwave oven, heat resistance, etc. are also required, and therefore, the vapor deposition layer of an inorganic oxide having these suitability and performance together with excellent gas barrier properties is used as the gas barrier layer. It is preferable to use.

As the inorganic oxide vapor deposition layer, specifically,
A heat resistant film such as a biaxially stretched polyethylene terephthalate film so that the thickness of alumina, silica, zinc oxide, magnesium oxide, etc. is about 200 to 1000 Å by the CVD method or PVD method such as vacuum deposition, ion plating and sputtering. It can be vapor-deposited on the surface and used.

By adopting such a constitution, in addition to the effect of the invention described in any one of claims 1 to 3, an excellent gas barrier property can be imparted to the composite container, so that the container is filled. The storability of the contents can be further improved.

The invention according to claim 5 is the composite container according to any one of claims 1 to 4, characterized in that in the composite container, the mass ratio of the paper is 51% by mass or more.

In order to adopt such a structure, the blank plate is used for both the side surface and the bottom surface of the container, a relatively thick paper board is used as the base material of the blank plate, and the injection is performed. In order to reduce the amount of the molding resin used as much as possible, it is necessary to limit the upper and lower edge portions of the container and the columnar vertical ribs that connect between them to the minimum, but it is feasible. Therefore, by adopting the above configuration,
In addition to the effects of the invention described in any one of claims 1 to 4, when the used container is discarded, for example, the calories burned can be reduced even if incinerated, and damage to the incinerator is prevented. be able to. Also, when the container material is recycled, the paper can be efficiently collected.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the composite container of the present invention will be described below. The composite container of the present invention is a blank plate obtained by punching out a laminated sheet in which at least paper and a plastic film are laminated, and inserted into a molding die,
A composite container formed by integrally molding a resin and a blank plate by injection-molding a resin, wherein the innermost layer of the blank plate and the injection-molded resin portion are heat-resistant polypropylene-based resin or polyester-based resin. The structure is basically made of resin and a foamed layer of resin is provided on the outer surface of the blank plate, and the blank plate is provided with a vapor deposition layer of inorganic oxide as a gas barrier layer.

Laminated sheets of various laminated constitutions can be used for the blank plate of such a composite container, and the following constitution can be mentioned as a typical laminated constitution. (1) (Outer) low-density polyethylene layer (foaming layer) / (printing) paper / medium density polyethylene layer / non-stretched polypropylene layer (2) (Outer) low-density polyethylene layer (foaming layer) / (printing) paper / medium Density polyethylene layer / Polypropylene layer (co-extrusion layer) (3) (Outside) Low-density polyethylene layer (foaming layer) / (printing) paper / Medium density polyethylene layer / polypropylene layer (co-extrusion layer) / Unstretched polypropylene layer (4) ) (Outside) Low density polyethylene layer (foaming layer) / (Printing) paper / Linear low density polyethylene layer / Unstretched polypropylene layer (5) (Outside) Low density polyethylene layer (foaming layer) / (Printing) paper / Low density polyethylene layer / polypropylene layer (co-extruded layer) / non-stretched polypropylene layer (6) (outer) Low density polyethylene layer (foamed layer) / (printing) paper / medium density polyethylene layer / inorganic oxide Deposition layer
Biaxially stretched polyethylene terephthalate film / adhesive / non-stretched polypropylene film (7) (outer) low-density polyethylene layer (foamed layer) / (printing) paper / non-stretched polypropylene layer Alternatively, since a polypropylene layer formed by co-extrusion is laminated, it is a configuration suitable when a polypropylene resin is used as the injection molding resin. (8) (Outside) Low-density polyethylene layer (foaming layer) / (printing) paper / polyethylene terephthalate layer In the above configuration, when the polyethylene terephthalate layer is laminated as the innermost layer, polyethylene terephthalate is used as the injection molding resin. The configuration is suitable for. (9) (Outer) low-density polyethylene layer (foaming layer) / (printing) paper / polybutylene terephthalate layer In the above configuration, since the polybutylene terephthalate layer is laminated as the innermost layer, polybutylene terephthalate is used as the injection molding resin. This is a configuration suitable when using. In addition to the above, various configurations can be adopted. Further, the thickness of the paper and each resin layer can be appropriately set depending on the size of the container and the contents to be filled.

In the blank plate structure, the outermost foamed layer is made of low-density polyethylene (hereinafter, LD).
Although a structural example using the PE) layer is shown, a copolymer of ethylene and α-olefin, vinyl acetate or the like can be preferably used in addition to LDPE.

Such a foam layer can be formed by extruding the resin on a paper surface or a printing surface of a paper by an extrusion coating method.
The resin emulsion or dispersion may be applied, dried and laminated. The extrusion coating method has the advantage of high-speed processing and excellent productivity, and the coating and drying method has a slightly lower productivity, but has the advantage that a foam layer can be easily formed in a pattern only on the necessary parts. There is. In addition, as described above, the foam layer is not foamed before injection molding and 130 to 15 after molding the composite container in order to smoothly perform insert injection molding of the blank plate.
By passing through a heating furnace at about 0 ° C., it is possible to easily foam by utilizing the moisture contained in the paper. The expansion ratio of such a foam layer is usually about 10 to 20 times,
The thickness of the resin in the foam layer is 20 to 80 μm before the foaming.
By setting the thickness to m, preferably 40 to 60 μm, good heat insulation can be obtained.

The paper used as the base material of the blank board is not particularly limited, but as described above, the use of paperboard having a rice basis weight of 200 to 500 g / m ² reduces the rigidity of the container at low cost. It is preferable in that the foaming layer can be more easily foamed, and for example, a suitable one can be appropriately selected and used from cup base paper, ivory paper, card paper, coated ball and the like.

Next, on the inside of the paper, the above (7), (8),
As described in the configuration of (9), the innermost resin layer, in this case, a non-stretched polypropylene (CPP) layer, a polyethylene terephthalate (PET) layer, a polybutylene terephthalate (PBT) layer may be laminated. , (1) ~ (6)
As described in the above-mentioned constitution, an intermediate layer such as a medium density polyethylene (MDPE) layer, a linear low density polyethylene (LLDPE) layer and a low density polyethylene (LDPE) layer can be provided between the paper and the innermost layer. .

For such an intermediate layer, it is possible to strengthen the heat-resistant adhesive strength with paper by extruding a coating method or by laminating an innermost layer film formed in advance by an extrusion laminating method (sandwich laminating method). At the same time, it is preferable because the intermediate layer has a buffering effect, improves impact resistance such as drop strength of the container, and prevents pinholes during injection molding.

The intermediate layer includes an MDPE layer and an LLD.
Although either the PE layer or the LDPE layer is provided, when the foam layer on the outer surface of the blank plate (in this case, the LDPE layer) is foamed by heating, it is preferable not to foam the intermediate layer inside the paper, For that purpose, it is optimal to provide the intermediate layer with, for example, an MDPE layer having a melting point higher than that of the LDPE of the foam layer and a large difference therebetween. Only, LLDPE
The layer and the LDPE layer also have a thickness of 20 μm or more, and the total thickness of the resin inside the paper (the total thickness of the resin including the innermost layer) is made larger than the thickness of the outer foam layer, thereby forming an intermediate layer. The resin can be prevented from foaming, and at the same time, the adhesiveness to paper can be improved, so that it can be used favorably.

In the constitution (2), the MDPE layer as the intermediate layer and the polypropylene layer as the innermost layer are laminated as a co-extruded layer. By adopting such a constitution, the laminating process can be simplified. At the same time, the lamination strength of the intermediate layer and the innermost layer can be improved. In the configurations of (3) and (5), the intermediate layer is formed of a coextruded layer of an MDPE layer / polypropylene layer or an LDPE layer / polypropylene layer. The inner side, that is, the surface on which the innermost layer is laminated, is formed of the same resin as the innermost unstretched polypropylene layer, so the innermost unstretched polypropylene layer is extruded and has good adhesiveness and good productivity. It can be laminated.

When the resin for the foamed layer, the intermediate layer, and the innermost layer is laminated on the paper by extrusion coating, coextrusion coating, extrusion lamination, or the like, if necessary,
In order to improve the adhesive strength, the paper surface can be subjected to an easy-adhesion treatment such as flame treatment or corona discharge treatment.

When imparting a gas barrier property to the composite container, for example, the intermediate layer (MDPE layer) of the blank plate and the innermost layer (non-stretched polypropylene layer) are used as described in the constitution (6) above. The gas barrier property can be imparted by laminating a biaxially stretched PET film having a vapor-deposited layer of an inorganic oxide between the above and the above). In this case, as the vapor deposition layer of the inorganic oxide, the vapor deposition layer of alumina, silica, zinc oxide, magnesium oxide or the like can be used as described above.

The vapor-deposited layer of such an inorganic oxide may be formed of any one of the above-mentioned layers, but if it is formed of a plurality of layers, a more excellent gas barrier property can be obtained. In addition, such a vapor-deposited layer of an inorganic oxide improves adhesion thereof, or prevents damage such as cracks and effectively exhibits excellent gas barrier properties. Reactive acrylic resin, polyurethane resin, acrylic resin containing silane coupling agent, water-soluble polymer containing metal alkoxide, ethylene-vinyl for the purpose of gas barrier property improving layer, protective layer, etc. A resin layer such as an alcohol copolymer can be provided.

The blank plate having the structure described in (6) above is
For example, a biaxially stretched PET film provided with a vapor-deposited layer of an inorganic oxide and an unstretched polypropylene film of the innermost layer formed in advance are used with a two-component curable polyurethane adhesive with the vapor deposition surface inside. Biaxially stretched PE of laminated film that is laminated by dry lamination method
The T-film surface and the inner surface of the paper can be manufactured by a method in which MDPE for the intermediate layer is used to bond them by an extrusion laminating method (sandwich laminating method).

Next, the resin of the innermost layer of the blank plate has resistance to the contents, and at the same time, adheres well to the resin for injection molding, imparts excellent sealing property to the composite container, and the contents of the microwave oven. It is necessary to have heat resistance to withstand such heating by heating, and for that purpose, it is preferable to use the same type of resin in combination with the resin for injection molding. For example, when an unstretched polypropylene layer is used as the innermost layer, a polypropylene resin such as polypropylene or a copolymer thereof is used as the resin for injection molding, and a polyester such as an unstretched polyethylene terephthalate layer or a polybutylene terephthalate layer is used as the innermost layer. When using a resin layer, it is preferable to use a polyester resin such as polyethylene terephthalate or polybutylene terephthalate, or a copolymer thereof as a resin for injection molding.

[0039]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described more specifically below with reference to the drawings. FIG. 1 is a side view showing the configuration of an embodiment of the composite container of the present invention. FIG. 2 is a cross-sectional view taken along the line AA of the composite container shown in FIG. FIG. 3 is a development view showing the configuration of an example of a blank plate used for the composite container shown in FIG.
FIG. 4 is a development view showing a configuration of an example of the blank plate used in the composite container shown in FIG. 1, which is different from FIG. 3. It should be noted that the present invention is not limited to these drawings unless the gist thereof is exceeded.

The composite container of the present invention has, for example, FIGS.
Can be configured as shown in. The composite container 100 shown in FIGS. 1 and 2 uses, for example, a blank plate having a configuration as shown in FIG. 3 or FIG. 4 and is formed into a container shape and inserted into an injection molding die, It can be manufactured by injection molding a resin. The composite container 100 shown in FIGS. 1 and 2 is substantially manufactured by using the blank plate 50 shown in FIG. 3 and by using the blank plate 60 shown in FIG. The shape of the former is different from that of a round container and the latter is like a rectangular container. However, the side view (Fig. 1) and the sectional view taken along the line AA (Fig. 2) are common, and therefore they are used for both. It was

The blank plate 50 shown in FIG. 3 is used for manufacturing a tapered round composite container having a circular cross section, and has a circular bottom plate 2 at the center thereof and side peripheral walls above and below it. A fan-shaped side plate 1a or side plate 1 forming a half circumference.
b is provided in a row, a crease 4a is provided between the bottom plate 2 and the side plate 1a, and a crease 4b is provided between the bottom plate 2 and the side plate 1b.
And a cutout portion 3 is provided at a position corresponding to the injection port of the resin for injection molding in the central portion of the bottom plate 2.

Such a blank plate 50 can be easily manufactured by punching out the above-mentioned laminated sheet. In addition, the blank plate 50 is formed into a round container by inserting it into a female mold of a molding mold including a male mold and a female mold, and after closing the mold with the male mold, the bottom plate 2 is placed in the mold. By injecting the resin from the side of the cutout 3 and integrally molding the blank plate 50 and the resin, the composite container 100 having the configuration shown in FIGS. 1 and 2 can be manufactured.

The blank plate 60 shown in FIG. 4 is used for manufacturing a tapered rectangular composite container having a square cross section. In this case, a rectangular bottom plate 2 is provided at the center of the blank plate 60. A substantially fan-shaped side plate 1a or side plate 1b forming a half circumference of each side peripheral wall is continuously provided on the bottom plate 2 and
And a side plate 1a are provided with a pushing ruled line 4a, and a bottom plate 2 and a side plate 1b are provided with a pushing ruled line 4b.
At the position corresponding to the four corners of the square composite container side of b, 3
A set of vertical pressing rules 5a, 5b, 5c, 5d is provided, and further, a notch 3 is provided at a position corresponding to the injection port of the injection-molded resin at the center of the bottom plate 2. In addition, the vertical pressing rules 5a, 5b, 5c, 5 provided on the side plates 1a, 1b.
d is provided as necessary so that this part can be gently bent when the tapered rectangular container is formed by bending this part, and can be removed if unnecessary.

Such a blank plate 60 can also be easily manufactured by punching out the above-mentioned laminated sheet. In addition, the blank plate 60 is formed into a rectangular container shape by inserting it into a female mold of a molding mold composed of a male mold and a female mold, and after closing the mold with the male mold, the bottom plate 2 of the bottom plate 2 is inserted into the mold. By injecting a resin from the side of the cutout 3 and integrally molding the blank plate 60 and the resin, the composite container 100 having the configuration shown in FIGS. 1 and 2 is formed as in the case of the blank plate 50. It can be manufactured.

The composite container 100 shown in FIGS. 1 and 2 has the blank plate 50 or the blank plate 60 as described above, for example, in a female mold of a molding die composed of a male mold and a female mold.
By inserting the bottom plate 2 at the top as a male type, the bottom plate 2
Side plate 1a and side plate 1b, which are continuously provided on both sides of the
It is folded back by 4b and is formed so as to form a peripheral side wall, and is assembled into a tapered round or square container shape in a molding die.
Then, after the mold is closed with a male mold, the resin is injected from the notch 3 side of the bottom plate 2 into the molding die, so that the resin is spread from the center part of the bottom plate 2 to the bottom side connecting resin part 8 and the leg part 7. Further, the resin is injected into the longitudinal bone resin portion 6 at the abutting portion of the side plates 1a and 1b on both side end portions, and the rim bone resin portion 9 and the flange portion 10 which are continuous with the longitudinal bone resin portion 6 to form a frame-shaped injection molding resin. The blank plate 50 or the blank plate 60 is integrally molded to manufacture the tapered round or square composite container 100.

The present invention will be described in more detail below with reference to specific examples. (Embodiment 1) FIG. 3 shows a composite container having the structure shown in FIGS.
It will be produced using a blank plate of the configuration shown in
Using polypropylene as a resin for injection molding and punching a laminated sheet having the following configuration as a blank plate, insert injection molding and a heat-foaming process were used to form a tapered round composite container of Example 1. It was made. [Configuration of Blank Plate] (Outside) LDPE Layer (Foaming Layer) (Thickness 40 μm) / Copper Base Paper (Basis Weight 300 g / m ² ) / MDPE Layer (Thickness 15)
・ Polypropylene layer (thickness 20 μm) (co-extrusion coat) / CPP layer (thickness 30 μm) Incidentally, the container volume is 200 ml, the leg height is 1 mm, and the flange top surface width is 4 mm. Then, the foam layer on the surface was heated under the heating condition of 150 ° C. for 3 minutes to foam.

(Embodiment 2) In the construction of the composite container of the above-mentioned Embodiment 1, except that the laminated sheet used for the blank plate was replaced with the following construction in order to impart gas barrier property to the container, The same processing as in Example 1 was carried out to prepare a tapered round composite container of Example 2. [Configuration of Blank Plate] (Outside) LDPE Layer (Foaming Layer) (Thickness 40 μm) / Copper Base Paper (Basis Weight 300 g / m ² ) / MDPE Layer (Thickness 15)
μm) / alumina vapor deposition layer (thickness 400Å) / biaxially stretched polyethylene terephthalate film (thickness 12 μm) /
Adhesive / CPP layer (thickness 30 μm)

(Tests and Results) The composite containers of Example 1 and Example 2 prepared as described above were filled with water and heated in a microwave oven until the temperature of the contents reached 95 ° C.,
Both have no liquid leakage or charring of the blank board paper,
The container itself had little deformation and had good heat resistance. Even when the above-mentioned composite container was held by hand, the composite container did not feel much heat and could be held safely and had a good heat insulating property. In addition, the gas barrier property (oxygen permeability) of the composite container was measured by using an oxygen permeability measuring device (OXTRAN) manufactured by MOCON, and the oxygen permeability per container was 23 ° C. and the relative humidity of the outside was 45%. As a result of performing a purge for 3 days at an inner relative humidity of 90%, the composite container of Example 1 was found to be 1.5 ml / piece · day ·
The pressure was 0.1 MPa, whereas the composite container of Example 2 had 0.07 ml / piece · day · 0.1 MPa, which showed excellent oxygen barrier property due to the vapor deposition layer of the inorganic oxide (alumina in this case). The improvement effect was recognized.

[0049]

As described above in detail, according to the present invention, a blank plate obtained by punching out a laminated sheet in which at least paper and a plastic film are laminated is inserted into a molding die, and a resin is injection-molded. By doing so, it is a composite container formed by integrally molding a resin and a blank plate, and the adhesiveness between the injection molded resin and the blank plate is good, and the contents are liquid contents such as various beverages and soups. Even if it is, it can be safely hermetically sealed, and it can be heated by a microwave oven or hot warmer, etc., and it has heat resistance to withstand it, and even when the contents are heated, the container is not hot to hold by hand. It is possible to provide a highly productive composite container having a certain degree of heat insulation property, which further enhances the gas barrier property and can improve the storability of the contents, and which has excellent suitability for use. Achieve the results.

[Brief description of drawings]

FIG. 1 is a side view showing a configuration of an embodiment of a composite container of the present invention.

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

3 is a development view showing a configuration of an example of a blank plate used for the composite container shown in FIG. 1. FIG.

FIG. 4 is a development view showing the configuration of an example of the blank plate used in the composite container shown in FIG. 1, which is different from FIG. 3.

[Explanation of symbols]

1a, 1b Side plate 2 Bottom plate 3 notches 4a, 4b pushing ruled lines 5a, 5b, 5c, 5d Vertical pressing ruled lines 6 Vertical bone resin part 7 legs 8 Bottom connection resin part 9 Oral bone resin part 10 Flange part 50, 60 Blank board 100 composite containers

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI theme code (reference) B65D 1/09 B65D 1/00 BC (72) Inventor Tokuyuki Shiina 1-chome, Ichigaya-ga, Shinjuku-ku, Tokyo No. 1 Dai-Nippon Printing Co., Ltd. F term (reference) AK01B AK06D AK06J AK07B AK07C AK41B AK41C AL01D BA04 BA05 BA07 DA01 DG10A DJ01D EH362 EH66E GB16 JJ02 JJ03 YY00B YY00C

Claims (5)

[Claims] 1. A blank plate obtained by punching out a laminated sheet in which at least paper and a plastic layer are laminated is inserted into a molding die, and the resin is injection-molded to integrally mold the resin and the blank plate. In the composite container formed as described above, the innermost layer of the blank plate and the injection-molded resin portion are formed of polypropylene resin or polyester resin, and a foam layer of resin is provided on the outer surface of the blank plate. A composite container having heat resistance and heat insulation properties. 2. The composite container according to claim 1, wherein the thickness of the polypropylene resin or the polyester resin of the innermost layer of the blank plate is 30 μm or more and 200 μm or less. 3. The composite container according to claim 1, wherein the foam layer on the outer surface of the blank plate is formed of low density polyethylene or a copolymer thereof. 4. The composite container according to any one of claims 1 to 3, wherein the blank plate is provided with a vapor deposition layer of an inorganic oxide. 5. In the composite container, the mass ratio of paper is 5
It is 1 mass% or more, The composite container in any one of Claim 1 thru | or 4 characterized by the above-mentioned.