JPH09323743A - Container with lid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve sealability and removability of a lid in a container comprising a container body made of a thermoplastic resin foam sheet with a fitting part provided on an inner peripheral face of an opening and a lid fitted by specifying difference in sizes in a horizontal direction of the fitting part, density and flexural modulus of the foam sheet. SOLUTION: In a container with lid used for microwave-cooked food, noodle in a cup or the like, an approximately horizontal stage 3 for mounting a lid 2 is formed along an entire peripheral direction of an opening of a container body 1 made of a thermoplastic resin foam sheet on its internal face. An upper end of an opening side wall 31 formed upward from an outer end of the stage 3 is made to protrude inward to provide a wide fitting part 32, and a flange 4 horizontally protruding outward from the upper end of the opening side wall 31 is formed. At this time, difference in sizes in a horizontal direction of the fitting part 32 is 0.2 to 3.0 mm, while a material having density of as the thermoplastic foam sheet to improve sealability.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a container with a lid whose lid fits tightly with the container, and is suitable for containing heated food used in microwave cooked foods, cup noodles, convenience store bento, etc. A container with a lid.

[0002]

2. Description of the Related Art With the spread of convenience stores and changes in lifestyles, consumption of food and drink in disposable containers, which are used for eating and drinking just by pouring hot water for a few minutes or heating in a microwave oven, has increased rapidly in recent years. ing.

As a container used for these, it is desirable to use an inexpensive and lightweight resin container, the inside of which is hermetically sealed by fitting a lid separate from the container body. This is because the lid is detachable and convenient because it does not require additional packaging for transportation, display, or heat treatment. Further, it is desirable to use a packing that does not require a packing part because of cost savings. As such a container, for example,
It is disclosed in Japanese Utility Model Publication No. 62-1089 and Japanese Utility Model Publication No. 5-26013.

However, in these conventional resin containers with a fitting lid, the sealing property or the removability by fitting (the performance that the lid is easily attached and detached) is not sufficient, or
Microwave resistance or heat insulation was not sufficient. If the heat insulating property is poor, the container cannot be held with bare hands after pouring hot water or other heat treatment.

In order to provide sealing and detachability by fitting, one of the container body and the lid is made of an elastic soft material,
The other must be made of a hard or semi-hard material. As a typical example of such a container, a container body and a lid body are respectively composed of a polypropylene resin and a polystyrene resin sheet, or a polystyrene resin foam and a sheet of a polypropylene resin. . In the former case, if one of the sealability and the detachability is sufficient, the other is not sufficient. Further, if the container body is not made of foam, the heat insulation is not sufficient. The latter can obtain a satisfactory performance in a narrow range in any of the sealability and the detachability which are obtained to some extent. It is considered that the polystyrene resin foam has insufficient elasticity and toughness. In particular, it is difficult to impart microwave resistance to polystyrene resin without laminating a heat resistant film or the like.

[0006]

SUMMARY OF THE INVENTION In the above-mentioned utility model publication, there is a very simple description that a foam sheet of polypropylene resin or the like can be used as a container body.

However, when a conventional container having a general shape is composed of a general resin foam sheet, it is impossible to obtain the above-mentioned excellent sealing property and detachability.

In view of the above-mentioned problems, the present invention provides an inexpensive and lightweight container which is excellent in both the sealing property and the detachability of the main body container and the lid, and further has the microwave oven resistance and the heat insulating property. It is a thing.

[0009]

A container with a lid according to claim 1 of the present invention comprises a container body formed of a thermoplastic resin foam sheet and a synthetic resin lid body that can be attached to the container body. In a container with a lid, in which a fitting portion is provided on the inner peripheral surface of the opening of the lid, and the outer surface of the lid is fitted to the fitting portion, the fitting portion of the container body has a horizontal dimension. The difference is 0.2 to 3.0 mm, and the density and bending elastic modulus of the thermoplastic resin foam sheet are 0.08 to
It is characterized by being 0.6 g / cm ³ and 200-610 MPa.

A lidded container according to claim 2 is the lidded container according to claim 1, wherein the thermoplastic resin foam sheet is polypropylene resin, polyethylene terephthalate resin, polyethylene naphthalate resin, or other microwave resistant cooking. It is characterized by comprising a thermoplastic resin having a property.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION As the thermoplastic resin used in the present invention, all general resins can be used. Polypropylene resin, polyethylene terephthalate resin, polyethylene naphthalate resin, or other thermoplastic resin having microwave oven resistance is preferable for a container for containing heated food. This is because these have excellent heat resistance and other durability, excellent water resistance and oil resistance, and do not absorb moisture. Particularly preferred resins include polyethylene terephthalate resin, polyethylene naphthalate resin, and other heat-resistant thermoplastic polyester resins. These are resins that are particularly stable and have excellent microwave oven cooking resistance.

Further, it is possible to use one obtained by laminating a thermoplastic resin non-foamed sheet or film on one or both sides of the thermoplastic resin foamed sheet. The density and bending elastic modulus of the laminated sheet may be within the above ranges, but the lamination is
It is desirable to perform the process between a foam sheet and a non-foam sheet or film made of the same resin in terms of easiness of production.

The laminated non-foamed sheet or film may be subjected to pattern printing or solid printing.

In the density of the thermoplastic resin foam sheet, when non-foam resin is laminated, the density of the portion excluding the laminated portion is 0.08 to 0.60 g / cm ³ , preferably 0.15. Is about 0.35 g / cm ³ . When the density exceeds this range, the heat insulation becomes poor, and when the density falls below this range, the resistance to repeated deformation is insufficient. In the present specification, when a non-foam resin is laminated, the density of the portion excluding the laminated portion is defined as the density of the thermoplastic resin foam sheet.

The bending elastic modulus of the thermoplastic resin foam sheet before molding is 200 to 610 MPa, preferably 210 to 5
It is 20 MPa. The thickness of the sheet is 0.8-4mm
It is a degree.

The container of the present invention is provided with a fitting portion consisting of a projection, a recess or an undercut on the inner peripheral surface of the opening of the container body, and the fitting portion is provided with the outer surface of the lid. It is a container with a lid to be fitted. In this specification, when a non-foam resin is laminated, the elastic modulus of the laminate is taken as the elastic modulus of the thermoplastic resin foam sheet.

The fitting portion of the container body of the container of the present invention has a dimensional difference in the horizontal direction of 0.2 to 3.0 mm, preferably 0.5 mm to 2.5 mm.

When the above dimensional difference is smaller than 0.2 mm,
Also, when the bending elastic modulus of the sheet is smaller than the lower limit value of this range, the detachability between the container body and the lid is excellent, but the adhesion between the two is insufficient, and the required sealing performance is required. Therefore, both can be easily separated by a small external force.
On the contrary, in the case where the above-mentioned dimensional difference is larger than 3.0 mm and the flexural modulus is larger than the lower limit value of this range, the adhesion is excellent, but the detachability is not sufficient.

The wall thickness of the side wall of the container body is 0.3 to 4.
It is 0 mm, preferably 0.8 to 3.5 mm.

If the height of the fitting portion of the container body is less than 3 mm, the lid is easily removed, and depending on the size of the container, it is usually 5 to 4.
0 mm.

The lid is made of synthetic resin and is formed from a non-foamed sheet or a foamed sheet. For example, polystyrene resin, polypropylene resin, polyethylene terephthalate resin, polybutylene terephthalate resin, polyethylene naphthalate resin and the like are used. Alternatively, a printed film may be attached.

[0022]

Embodiments of the present invention will be described below.

Regarding a container having a typical pot shape as shown in FIGS. 1 to 3, the container body is made of a polypropylene resin foam and a polyethylene terephthalate resin foam sheet, and the lid is made of a corresponding non-foam sheet. Was molded by. These moldings are performed by hot pressing, and when molding the container body, the diameter and depth of the opening in the male mold are 180 mm and 40 mm, respectively, and the clearance between the male mold and the female mold is 2.0 mm. did.

(Basic Shape of Container) The shape of the container of the embodiment will be described with reference to FIGS.

As shown in the perspective view of FIG. 1, a container main body 1 corresponding to the main body of the pan and a separate lid 2 corresponding to the lid of the pan.
Consists of The container body 1 has a substantially horizontal step portion 3 on the inner surface of which the lid body 2 can be placed over the entire circumference of the opening portion, and the opening side wall 31 formed upward from the outer end of the step portion 3. The upper end portion of the is projected inward to form a wide fitting portion 32 (FIG. 2). Further, the container body 1 is provided with a flat annular flange portion 4 that horizontally projects outward from the upper end of the opening side wall 31, and the flange portion 4 is further provided with two flat crescent-shaped handle portions 41. It is provided at the farthest position. At the center of the bottom surface of the container body 1, a recess 51 as viewed from below is provided in a truncated cone shape. The lid 2 is composed of a flat circular ceiling portion 6, a brim portion 8 corresponding to the brim portion 4 of the container body, and a square groove portion 7 between the brim portion 8 and the ceiling portion 6. Is formed at a position lower than the surface of the ceiling portion 6, and the joint between the ceiling portion 6 and the groove-shaped portion 7 is rounded in cross section. The bottom wall 71 and the outer side wall 72 of the channel portion 7 engage the step 3 and the opening side wall 31 of the container body. Further, on the outer side wall 72, a receiving portion 73 corresponding to the fitting portion 32 protruding from the opening side wall 31 is formed, whereby the container body 1 is formed.
And the lid 2 are fitted (FIG. 2). On the other hand, in the center of the ceiling portion 6, there is formed a truncated cone-shaped knob portion 61 corresponding to the concave portion 51 on the bottom surface of the container body 1, and when stacking a plurality of containers, the concave portion 51 on the bottom surface and the knob portion of the lid body are formed. Part 6
The mating with 1 facilitates stacking (FIG. 3).

A U-shaped notch is provided in the middle of the edge of the knob portion 61 and the edge of the ceiling portion 6 to form a steam hole 62.

In this embodiment, the fitting portion 32 of the container body
May be one in which a linear protrusion is provided in the middle of the opening side wall 31 in the vertical direction, or may be an undercut in which the entire opening side wall 31 is inclined. or,
The best sealing performance is obtained when the fitting portion 32 extends over the entire circumferential direction, but it may be provided intermittently in the circumferential direction or divided into several places depending on the application. In applications where the sealing property is not particularly required, the fitting portion may be provided over about 20% or more of the entire circumference. Here, it is assumed that the receiving portion 73 of the lid body 2 corresponds to the fitting portion 32 of the container body.

The steam holes 62 may be circular, elliptical, polygonal or the like, and various cutouts of the entire circumference and cutouts of only a half circumference are conceivable. As a method of preventing it, it is possible to attach a sticker such as a product label.

Since the groove portion 7 is formed on the lid body 2, when the lid body is removed, foreign matter is collected in this groove and does not fall into the container.

(Specific Examples and Comparative Examples) Table 1 below.
The present invention will be described with reference to specific examples and comparative examples shown in FIGS.

In manufacturing the container body 1 described above, several kinds of resin foam sheet stocks having different densities, thicknesses, and elastic moduli are used, and the dimensional difference d of the fitting portion 32 in the horizontal direction is used.
(FIG. 2) was variously changed.

With respect to the obtained container, the adhesion between the container body 1 and the lid 2 and the detachability were evaluated. As for the adhesion, the container body 1 is filled with 20 g of water and the lid body 2 is fitted to
It was judged whether or not a gap was created between the container body and the lid when the knob portion 61 of the container was grasped and lifted. Regarding detachability, whether or not it can be done by simply pressing down the outer edge of the brim of the container body and lightly pushing the outer edge of the brim portion 8 of the lid 2 upward when detaching, In this case, it was judged whether or not it is possible to simply press each other lightly.

The lid body 2 is formed of a non-foamed sheet made of the same kind of resin as the container body 1 and having a thickness of 0.28 mm.

The flexural modulus was measured by a three-point bending test method with a span of 100 mm and a radius of curvature of 3.2 mm for the supporting part and the pressing part. In the laminated sheet in which the non-foamed body was laminated, a pressure wedge (a pressure portion at the midpoint of the span) was applied to the non-foamed body side.

(Examples 1 to 4) The resin foam sheet is made of polypropylene resin (PP) and has a density and a flexural modulus of 0.27 g / cm ³ and 406 MPa, respectively.
Alternatively, those having 0.20 g / cm ³ and 210 MPa (resin foam sheets 1 and 2) were used. The thickness of each sheet is 1.5 mm.

In molding the container from the resin foam sheet, the horizontal dimension difference d of the fitting portion 32 is 0.
The height of the fitting portion 32 was set to 5 mm or 2.5 mm and 7 mm.

Table 1 summarizes the conditions and results.
In either case, the adhesion and the detachability between the container body 1 and the lid body 2 were both good.

[0038]

[Table 1] (Comparative Examples 1 to 4) The horizontal dimension difference d of the fitting portion is set to 0.1 mm.
Alternatively, the container was molded under the same conditions as in Examples 1 to 2 or 3 to 4 except that the container was 3.5 mm.

Table 2 summarizes the conditions and results.
Only one of the adhesiveness and the detachability between the container body 1 and the lid body 2 was good, and the other was not good. When the horizontal dimension difference d of the fitting portion 32 is 0.1 mm,
Although it was excellent in detachability, the adhesiveness was insufficient. When the dimension d of the fitting portion was 3.5 mm, the adhesiveness was excellent, but the detachability was insufficient.

[0040]

[Table 2] (Examples 5 to 10) Example 5 was used as a resin foam sheet.
Nos. 7 to 7 made of polypropylene resin (PP) and having flexural modulus of 250, 540 and 253 MPa (resin foam sheets 3, 4 and 5) were used, and in Examples 8 to 10, polyethylene terephthalate resin ( PET) having a bending elastic modulus of 385, 454 and 520 MPa (resin foam sheets 6, 7 and 8) were used. Here, in Examples 7 and 10 (resin foam sheets 5 and 8), 0.28 mm-thick non-foam sheets made of the same resin as the foam sheets were laminated.

The horizontal dimension difference d of the fitting portions was set to 0.5 mm.

Table 3 collectively shows specific conditions and results. In all cases, the adhesion and the detachability between the container body 1 and the lid body 2 were good.

[0043]

[Table 3] (Comparative Examples 5 to 10) The resin foam sheet is made of polypropylene resin (PP) and has a density and a flexural modulus of 0.068 g / cm ³ and 8 MPa, respectively, or 0.63.
Those having 0 g / cm ³ and 1300 MPa (resin foam sheets 9 and 10) were used. The thickness of the sheet is 1.49m
m and 1.10 mm.

When molding the container from the resin foam sheet, the horizontal dimension difference d of the fitting portion is 0.1 m.
m, 0.5 mm or 3.5 mm.

Table 4 summarizes the conditions and results.
Only one of adhesion and detachability between the container body and the lid was good, and the other was not good. When the density of the resin foam sheet is low and the elastic modulus is extremely low accordingly, the detachability is excellent but the adhesiveness is poor regardless of the horizontal dimension difference d of the fitting portion. Was enough. When the density of the resin foam sheet is high and the elastic modulus is extremely high accordingly, the adhesiveness is excellent, but the detachability is not good, regardless of the horizontal dimension difference d of the fitting portion. Was enough.

[0046]

[Table 4]

[0047]

Since the container with lid of the present invention is provided with the specific fitting portion, it is excellent in both the sealing property and the detachability of the main body container and the lid. Further, when a thermoplastic resin foam sheet such as polypropylene or polyester having heat resistance such as microwave resistance and heat insulation is used, a container with a lid suitable for containing heated food is provided.

[Brief description of drawings]

FIG. 1 is a perspective view showing a shape of a container according to an embodiment.

FIG. 2 is a schematic vertical cross-sectional view showing a fitting portion between the container body and the lid body of the container of the embodiment.

FIG. 3 is a schematic vertical cross-sectional view showing the fitting between the bottom surface of the container body and the top surface of the lid when the containers of the examples are stacked.

[Explanation of symbols]

 1 Container body 2 Lid body 3 Step portion 32 Fitting portion 4 Container body collar portion 41 Handle portion 61 Knob portion 62 Steam hole 7 Groove portion 8 Lid portion of lid d Horizontal dimension difference of fitting portion 32

Claims (2)

[Claims] 1. A container body formed of a thermoplastic resin foam sheet, and a synthetic resin lid which can be adhered to the container body.
In the lidded container in which a fitting portion is provided on the inner peripheral surface of the opening of the container body, and the outer surface of the lid body fits into the fitting portion, the fitting portion of the container body is horizontal. Is 0.2 to 3.0 mm, the thermoplastic resin foam sheet has a density and a flexural modulus of 0.08 to 0.6 g / cm ³ and 200 to 61, respectively.
A container with a lid, which is 0 MPa. 2. The container with a lid according to claim 1, wherein the thermoplastic resin foam sheet is polypropylene resin,
A container with a lid, which is made of polyethylene terephthalate resin, polyethylene naphthalate resin, or other thermoplastic resin having microwave resistance.