JP2002293328A - Food container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small wooden box-like food container wherein a frame material and an inside container ca be easily bonded to each other, sufficient bonding strength and integrity being retained, and smell peculiar to adhesives is not produced, while a malodor is not generated even if the container is heated by a microwave oven, resulting on giving no unpleasant feeling. SOLUTION: The food container A consists of a frame material 1 composed of an expanded thermoplastic resin and an inside container 2 composed of a thermoplastic resin and fitted in the frame material 1. The outer periphery 4 of the inside container 2 is fitted on the upper end of the material 1 to bond the periphery 4 to the upper end of the material 1 using a synthetic rubber hot-melt adhesive.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a food container obtained by combining a frame member made of a thermoplastic resin foam and an inner container made of a thermoplastic resin.

[0002]

2. Description of the Related Art A simple folded box-shaped food made by combining a frame material made of a thermoplastic resin foam and an inner container made of a thermoplastic resin fitted to the frame material. Containers are widely used as containers for various foods such as lunch containers and prepared dishes, because they have a better appearance and are more stable in form than synthetic resin containers formed integrally.

[0003] As this type of folded box-shaped container, for example, Japanese Patent Application Laid-Open No. 9-255066 discloses a container comprising a frame member made of a foamed synthetic resin and an inner container called a bottom plate formed from a thin sheet of synthetic resin. , The frame material and the inner container are integrated by heat fusion.

In the case of this proposed container, a foam of a relatively low melting point synthetic resin such as a polystyrene resin used for a frame material and a relatively high melting point such as a polypropylene resin used for an inner container are used. Since it is difficult to heat-seal with the synthetic resin of the above, the inner container is made of a two-layered sheet in which a relatively low melting point synthetic resin is laminated as a coating layer on a base layer of the resin. It enables fusion.

As a result, the cost of the inner container itself increases,
Further, it is necessary to heat-bond one by one using a hot plate, which causes a problem in productivity.

Further, Japanese Utility Model Application No. 57-6596 (Japanese Utility Model Application Publication No.
No. 8-109917) discloses a container comprising a frame material of expanded polystyrene resin and an inner container made of a polypropylene-based resin fitted into the frame material from above. Is adhered to the upper surface of the frame material to integrate them.

In this case, if an organic solvent-based hot-melt adhesive such as a vinyl acetate-based adhesive generally used in the prior art is used, when the adhesive is cooled, the adhesiveness is reduced and sufficient adhesiveness is obtained. Adhesion work requires skill because, in some cases, a force cannot be obtained and re-attachment cannot be performed. In addition, organic solvent-based adhesives such as vinyl acetate have an odor peculiar to the adhesive,
When the food is stored in a microwave oven or the like while being stored, an unpleasant odor due to the adhesive is generated, giving the user discomfort.

In addition, a ridge is formed on the outer peripheral surface of the inner container, the peripheral edge of the inner container is fitted on the upper portion of the frame material, and the ridge provided on the outer peripheral surface of the side wall is further fitted with the inner peripheral surface of the frame material. It has been considered that the bonding can be omitted by fitting and engaging with the concave streak (for example, Japanese Patent Application Laid-Open No. 11-193015).
When the inner container is lifted from under the inner container, the inner container comes off from the frame material, which may result in a defective container.

SUMMARY OF THE INVENTION The present invention has been made in view of the above, and it is possible to easily perform a bonding operation between a frame material and an inner container, and to have a good integration between the frame material and the inner container and maintain a sufficient adhesive force. Further, the present invention provides a folded box-shaped food container which does not leave an odor peculiar to the adhesive and does not generate an unpleasant odor even when heated in a microwave oven or the like.

[0010]

According to the present invention, as a means for solving the above problems, there is provided a frame member made of a thermoplastic resin foam and an inner container made of a thermoplastic resin fitted to the frame member. Wherein the peripheral portion of the inner container is bonded to the frame material with a synthetic rubber-based hot melt adhesive.

According to this food container, the inner container made of thin synthetic resin can be held in a fixed state by the frame material, and the form is stable and can be used in a good appearance. In addition, since the inner container is adhered to the frame material, there is no need to use a two-layered sheet as the inner container, and the inner container can be obtained at low cost. In particular, since the synthetic rubber hot melt adhesive is used as the adhesive between the frame material made of thermoplastic resin foam and the thermoplastic resin inner container, when the inner container is lifted from the bottom, , And sufficient adhesive strength can be secured.
In addition, no odor peculiar to the adhesive remains, and no unusual odor is generated even when heated by a microwave oven or the like.

In addition, the synthetic rubber-based hot melt adhesive has tackiness (adhesiveness) even if cooled slightly, so that it is not necessary to apply a pressure after applying the adhesive during the bonding operation. In addition, re-sticking is also possible, so that the bonding operation can be performed with a margin, and it is also possible to bond while continuously sending a large number of pieces, thereby improving the productivity.

In the above-mentioned food container, the frame material is formed of a polystyrene resin foam, and the inner container is formed of a polypropylene resin sheet containing a filler or a polypropylene resin or polyester resin foam sheet. Particularly preferred.

That is, the polystyrene resin foam is
It is relatively inexpensive, has good moldability, is rigid, has good shape retention, and can be suitably used as a frame material for this type of container. The filler-containing polypropylene resin used for the inner container has heat resistance and excellent oil resistance, and can be heated by a microwave oven without any problem in a state in which food containing an oil component is stored. When the foamed sheet is made of the above-mentioned material, the foamed sheet has heat insulation properties, and when heated by a microwave oven or the like, the inner container is not hot even when touched by hands, and there is no fear of burns.

In the above-mentioned food container, a peripheral portion of the inner container has a flange shape to be in contact with an upper end surface of the frame material, and a synthetic rubber-based hot melt adhesive is partially applied to the peripheral portion. It is preferable that the adhesive is partially adhered to the upper end surface of the frame member, so that the amount of the adhesive used can be reduced, and there is no problem such as stringing of the adhesive during the bonding operation.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the embodiments shown in the drawings.

FIG. 1 is a perspective view showing a frame material and an inner container of a food container according to an embodiment of the present invention separated from each other. FIG. 2 is a sectional view showing a state where the frame material and the inner container are combined and adhered. Is shown.

The food container (A) of this embodiment has a substantially rectangular frame material (1) made of a thermoplastic resin foam, and a thermoplastic resin molded into the frame material (1) from above. And an inner container (2) composed of a body.

The frame material (1) is made of various thermoplastic resin foams such as polystyrene resin, and may be formed into a rectangular frame by in-mold foaming. On the top, using a foam plate material obtained by extruding the material resin into a long strip shape and foam molding, bending it into a frame shape such as a rectangle and abutting both ends, or joining a part by overlapping. The appearance of a folded box is often and preferably used. In particular, if a print such as a wood grain pattern is applied to this foam plate material, it becomes more attractive.

The inner container (2) is formed from a sheet material of a thermoplastic resin such as polypropylene resin containing a filler such as talc by means of vacuum forming or pressure forming, for example. Side wall to be fitted inside (3)
Has a peripheral portion (4) that protrudes outward from the upper end of the frame material in a flange shape and can be placed on the upper end surface of the frame material (1). In the case shown in the figure, the peripheral edge (4) is formed so that its outer peripheral edge (4a) is bent downward and fitted to the outer periphery of the upper end portion of the frame material (1). It has a generally hook shape. Also, a convex part (5) for partitioning is provided inside the inner container (2).
Are formed.

The inner container (2) is fitted to the frame material (1) from above, and the peripheral edge (4) is fitted to the upper end of the frame material (1). The peripheral portion (4) that is in contact with the upper end surface of the frame material (1) is partially adhered and fixed, particularly by a rubber-based hot melt adhesive. (6) shows the bonding portion.

This synthetic rubber-based hot melt adhesive is
Hot melt adhesives based on synthetic rubber (for example,
Product name Hirodyne 1540S: manufactured by Hirodine Co., Ltd.)
However, unlike an organic solvent-based adhesive such as a vinyl acetate-based adhesive, an irritating odor peculiar to the adhesive does not remain, and no unusual odor is generated even when heated. Further, since the adhesive exhibits an adhesive activity in a relatively low temperature range, even if the adhesive is slightly cooled after application, the adhesive has tackiness (tackiness), and the bonding operation can be performed with a margin.

The above synthetic rubber hot melt adhesive is
The entire surface of the peripheral portion (4) of the inner container (2) that is in contact with the upper end surface of the frame material (1) may be adhered, but in practice, as shown in the figure, an interval is provided. Partially,
Alternatively, it is preferable to adhere them in spots.

That is, when the entire surface is adhered to the upper end surface of the frame member (1), it is necessary to apply an adhesive to the entire surface of the adhesive portion using a roller or the like. The use of the roller may cause stringing of the adhesive and the like, resulting in poor appearance.However, when the adhesive is partially or spot-bonded as described above, the amount of the adhesive applied is small, and as described above, No problem occurs, the appearance is good, and the bonding operation can be easily performed.

As the inner container (2), various thermoplastic resins can be used. Among them, a thermoplastic resin excellent in heat resistance and oil resistance is suitably used. For example, a polypropylene resin containing a filler is one of them.

Examples of the filler include general inorganic fillers such as talc, calcium carbonate, shirasu, gypsum, carbon black, white carbon, magnesium carbonate, clay and natural silicic acid, and metal powder. Among them, talc is particularly preferred.

When the inner container (2) is formed from a non-foamed sheet of a filler-containing polypropylene resin or the like as in the above embodiment, when the inner container (2) is heated by a microwave oven or the like,
Since the bottom of the inner container (2) becomes hot, it is preferable to set the depth so that the bottom (2a) of the inner container (2) is slightly floated from the lower surface of the frame (1). . That is, with such a configuration, when heated by the microwave oven, the hand can be gripped without touching the bottom portion (2a) of the inner container (2), so that there is no fear of burns or the like.

The inner container (2) is preferably made of the above-mentioned polypropylene resin, more preferably a filled polypropylene resin or polyethylene terephthalate (P).
A container formed from a foamed sheet of a polyester resin such as ET) can also be used.

In this case, the bottom (2a) of the inner container (2)
Can be formed to be flush with the lower surface of the frame material (1) as shown in FIG. 3 or to project downward from the lower surface of the frame material (1) as shown in FIG. That is, since the inner container (2) made of a foamed sheet itself has a certain degree of heat insulating properties, when heated by a microwave oven,
The bottom (2a) does not become hot even when touched by hands, and there is no risk of burns. In addition, when this food container (A) is stacked in two layers, the bottom of the inner container of the upper container is the frame of the lower container. Since it fits inside the material, the stacked state is stabilized.

An example of the means for bonding the inner container (2) of the food container (A) to the frame material (1) will be described with reference to FIGS. 5 and 6.

An inner container (2) formed of a thermoplastic resin is mounted on a conveyer (10) such as a roller conveyor or a belt conveyor in a state where the inner container (2) is turned upside down, and is sent to an adhesive application section (11). It is positioned and stopped at a predetermined set position of the process section (11). This coating process section (11)
Above is a required number of hoses connected to a hot melt adhesive bath (20) containing synthetic rubber as a main component, for example, FIG.
The eight application nozzles (12) are arranged so as to be able to move up and down, and the application nozzle (12) descends with the stop operation of the inner container (2) to lower the inner container (2). Is set at a position of 1 to 2 cm above the peripheral edge (4), and air pressure acts on only the necessary application nozzles (12) according to the bonding mode such as 4-point, 6-point, and 8-point bonding. Thus, the adhesive is controlled to be sprayed. Thereby, the adhesive (6a) is applied in a spot manner as shown in FIG.

After the adhesive (6a) has been applied to the required places in this way, the inner container (2) is sent to the subsequent bonding step (13). Separately, the frame material (1) is supplied and set on the bonding step (13). Then, the inner container (2) sent to the bonding process section (13) is fitted over the frame material (1) by manual means or by mechanical means using a robot. Then, the peripheral part (4) to which the adhesive is applied is placed so as to fit to the upper end part of the frame material (1). Further, this is sent to the subsequent pressing step (14), and is pressed from above the peripheral edge (4) by the pressure roller (15) to be completely adhered.

While the inner container (2) is turned upside down, an adhesive is applied to the back surface of the peripheral portion (4), and the frame material (1) is fitted to the peripheral portion (4). It is also possible to place it in such a manner and press it as it is to bond it.

Thus, the peripheral portion (4) of the inner container (2)
Can be spot-bonded to the upper end surface of the frame material (1) at a plurality of places, and the food container (A) of the present invention as shown in FIG. 2 can be obtained.

The food container of the present invention thus obtained (A)
Is because the inner container (2) made of thermoplastic resin is bonded to the frame material (1) made of thermoplastic resin foam,
Even if the inner container (2) is made of a relatively thin sheet of thermoplastic resin, it has sufficient shape-retaining strength and can be used in a style like a folded box.

Further, since the inner container (2) and the frame member (1) are bonded and fixed by a synthetic rubber-based hot melt adhesive, even if they are bonded in a spot manner, Is good, and can hold the bonding strength without detaching the frame member (1) when the bottom part (2a) is lifted by hand.

Further, since the inner container (2) is bonded to the frame material (1), the inner container (2) can be formed of a single sheet material, and can have a two-layer structure. The adhesive is obtained at a lower cost than in the case of using a laminated sheet. Further, since the adhesive is not an organic solvent-based adhesive such as a vinyl acetate-based adhesive, there is no irritating odor peculiar to the adhesive and a microwave oven. No odor is generated even when heating is performed, and no discomfort is given to the user.

Moreover, this synthetic rubber-based hot melt adhesive exhibits an adhesive activity in a relatively low temperature range, and the tackiness (adhesiveness) does not decrease even if the applied adhesive is slightly cooled. The work can be performed with plenty of time, and re-pasting can be easily performed.

In particular, as shown in the illustrated embodiment, when the peripheral portion (4) of the inner container (2) is fitted to the upper end of the frame member (1), the inner container (2) and the frame member The integrity of (1) is further increased, and the inner container (2) is strong against the load acting on the inner container (2), and there is no fear of bottoming out. Further, because of the fitting structure of the peripheral portion (4), it becomes easy to combine a fitting cover (not shown) or a sealing cover fitted on the peripheral portion (4).

[0040]

As described above, according to the food container of the present invention, a frame material made of a thermoplastic resin foam and an inner container made of a thermoplastic resin are bonded using a synthetic rubber-based hot melt adhesive. Because it is made, it has good appearance and good shape retention, and even if it is partially adhered, it can maintain sufficient adhesive strength, and It has excellent integrity and does not come off when the container is lifted.

In addition, the synthetic rubber-based hot melt adhesive does not have an unusual odor peculiar to the adhesive, does not generate an unpleasant odor when heated, and can be used without giving any discomfort. In addition, the adhesive work can be carried out with a margin because it can maintain the adhesiveness even if it cools down a little, for example, while continuously sending the inner container through the adhesive application process section, the adhesive process section, the pressing process section. Adhesion is possible, productivity is good, and the inner container can be molded from a single layer of resin sheet,
It can be provided at low cost.

When the inner container is made of a polypropylene resin containing a filler, it has excellent heat resistance and oil resistance.
There is no problem in storing foods containing oily components and heating them in a microwave oven, and when using a foam of polypropylene-based resin or polyester-based resin, since it itself has heat insulation properties, It is not hot even if touched by hand,
There is no worry about burns.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of a food container of the present invention in which an outer frame material and an inner container are separated and shown.

FIG. 2 is a cross-sectional view showing a state where the outer frame member and the inner container are bonded to each other.

FIG. 3 is a sectional view showing another embodiment of the present invention.

FIG. 4 is a sectional view showing still another embodiment of the present invention.

FIG. 5 is a schematic side view of a bonding operation step.

FIG. 6 is a schematic perspective view illustrating a state where an adhesive is applied to an inner container;

[Explanation of symbols]

 (1) Frame material (2) Inner container (2a) Bottom part (3) Side wall part (4) Peripheral part (4a) Folded lower part (5) Partition convex part (6) Adhesive part (6a) Coated adhesive Agent

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) // C09J 121/00 C09J 121/00 4J040 B29L 22:00 B29L 22:00 C08L 25:06 C08L 25:06 F-term (reference) 3E033 AA10 BA13 DE11 FA04 GA03 3E035 AA20 BA02 BB01 BD10 3E061 AA02 AA04 AB09 AB10 DA02 DB01 DB11 4F071 AA02 AA12A AA13A AA20B AA22B AA43B AF44B AH05 CC02 CD01 A02TCA1A23A02A02A TN58 TN60 TN67 TQ03 4J040 DN071 EL051 JB01 LA06 LA11

Claims (3)

[Claims] 1. A frame material made of a thermoplastic resin foam, and an inner container made of a thermoplastic resin fitted to the frame material, wherein a peripheral portion of the inner container is made of a synthetic rubber-based material with respect to the frame material. A food container characterized by being bonded by a hot melt adhesive. 2. The frame according to claim 1, wherein the frame member is made of a polystyrene resin foam, and the inner container is formed from a filler-containing polypropylene resin sheet or a polypropylene resin or polyester resin foam sheet. Food containers. 3. A peripheral portion of the inner container has a flange shape to be in contact with an upper end surface of the frame member, and a synthetic rubber-based hot melt adhesive is partially applied to the peripheral portion, and an upper end surface of the frame member is provided. The food container according to claim 1 or 2, which is partially adhered to the food container.