JP2003252357A - Container with lid provided with inner fitting part - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a container with a lid provided with inner fitting parts in which a lid body is relatively easily fitted on and removed from a container main body while sealing properties of the inner fitting parts 11 and 31 between the container main body 10 and the lid body 30 are ensured. <P>SOLUTION: In the container main body 10 and the lid body to be fitted thereto, at least the inner fitting parts 11 and 31 are made in such a way that biaxially drawn resin raw materials are brought into plane contact with each other. It is preferable that the container main body is a laminate of a biaxially drawn polypropylene resin film on a foam polypropylene resin sheet and the lid body is a molded article of a biaxially drawn polystyrene resin sheet. <P>COPYRIGHT: (C)2003,JPO

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 provided with an inner fitting portion, and more particularly, a container with a lid suitable for accommodating food materials containing a large amount of liquid such as oden sold at stores such as convenience stores. Regarding

[0002]

2. Description of the Related Art With the spread of convenience stores and changes in lifestyles, heated foods containing a lot of liquid, such as oden, are put in the container body at the store, and then the lid is handed over to the customer. The sales style is increasing. In such a sales style, it is required that the container body has a required rigidity, that the lid body and the container body have a high sealing property, and that the lid body is easily attached and detached.

[0003] A container with a lid provided with an inner fitting portion is being used because it is easy to obtain a good sealing property. For example, in Japanese Patent Laid-Open No. 9-323743, a container body formed of a thermoplastic resin foam sheet and a synthetic resin lid that can be attached to the container body are used as a container for cup noodles, convenience store bento, etc. A container with a lid is described, which is provided with an inner fitting portion in which an outer peripheral surface of an outer surface of a lid body is internally fitted to an inner peripheral surface of an opening of a container body. In this container,
By making the density and bending elastic modulus of the thermoplastic resin foam sheet used for molding have specific values, it is attempted to improve both the sealing property and the detachability of the main body container and the lid.

Japanese Patent Laid-Open No. 11-314628 discloses that
In a container with a lid having an inner fitting portion of a similar shape, a container provided with an annular reinforcing member on the back surface side of the top plate portion of the container body in order to enhance rigidity and sealing performance of the container body. Have been described. As an example of the lid, there is a description that a thermoformed body of a stretched polystyrene sheet can be used. JP-A-9
JP-A-216649 describes a container with an inner fitting lid, which is provided with an annular projecting portion at an inner fitting portion of a container body and a lid body so as to enhance the hermeticity and prevent juice leakage. There is. Further, Japanese Patent Laid-Open No. 2001-315277 describes a molding container thermoformed from a material in which a biaxially stretched film is laminated on a polypropylene foam sheet having a specific cell diameter, and this container has a surface smoothness. Is good, and the adhesion to the lid of the container or the wrap film is improved.

[0005]

Among the containers with lids having the above-described conventionally known inner fitting portions, those described in (1) to (4) are for preventing liquid leakage, basically, the shape of the inner fitting portion. The present invention aims to improve the dimensional accuracy thereof, and further, to increase the strength of the inner fitting portion, and tightly fits the container body and the lid body to enhance the hermeticity. As a result, there is a problem that it is difficult to attach and detach the lid to and from the container body.At a store such as a convenience store, when the store clerk puts the ingredients such as oden together with the soup and puts on the lid, be careful. It is necessary to tighten the lid.
Also, when the customer opens the lid, the container carelessly tilts,
It is possible for the soup to spill out of the container. Also,
In the molded container described in (1), while the surface smoothness is good, the adhesion with the lid or the wrap film is improved, and as a result, the workability when the lid or the wrap film is detached is deteriorated. Soup is likely to spill out of the container. Further, a container obtained by thermoforming a polypropylene-based foamed sheet often has a variation in dimensional shrinkage per molding shot (for example, 16 pieces) after molding, and when the adhesion is too strong, It becomes easy to get things that make it difficult to attach and detach the lid.

The present invention has been made in view of the above circumstances, and it is relatively easy to attach / detach the lid to / from the container body while ensuring the sealing property at the fitting portion between the container body and the lid. Therefore, it is therefore an object of the present invention to provide a lidded container having an inner fitting portion that can be used very effectively when a food product containing a large amount of liquid such as oden is stored and sold at a store.

[0007]

[Means for Solving the Problems] In order to solve the above problems, many experiments were repeated to make the contact surface of the inner fitting portion between the container body and the lid body the contact surface between the biaxially stretched resin materials. By doing so, it was experienced that a high frictional force (grip force) was obtained on the contact surface, making it difficult for liquid to pass through.
As a result, even if the dimensional accuracy of the inner fitting part is lower than that of the conventional one, that is, even if there is a slight gap between the fitting parts, the leakage of the contents (liquid) is effectively prevented. I knew what I could do.

The present invention is based on the above findings, and a container with a lid having an inner fitting portion according to the present invention basically comprises a container body and a lid body that can be attached to the container body. The outer peripheral surface of the lid body is adapted to be internally fitted to the inner peripheral surface of the portion, and the biaxially stretched resin materials are in surface contact with each other at least in the inner fitting portion. And

In the container with a lid having the inner fitting portion according to the present invention, as will be described later, even if there is a slight gap in the inner fitting portion between the container body and the lid, the liquid leakage is almost completely caused. It was confirmed by experiment that it could be stopped. for that reason,
In the container with a lid according to the present invention, it is possible to easily attach and detach the lid to and from the container body while ensuring hermeticity, which facilitates the container filling operation of food materials with a lot of liquid such as oden at the store, Further, the purchaser can carry the container without causing liquid leakage and can reliably take out the food from the container body.

Conventionally, in the case of thermoforming a container using a foamed resin sheet such as a foamed polypropylene sheet as a material, there is a variation in the dimensional shrinkage rate per shot, resulting in poor fitting. In some cases, it cannot be used as a container with a lid, but according to the present invention,
As described above, since the allowable dimensional error (variation in dimension due to shrinkage) can be made large, it is possible to continuously form a container using such a material.

In the present invention, the biaxially stretched resin material is
It is a biaxially stretched film or a biaxially stretched sheet made of a resin, and is not limited to a single layer, and may be a multilayer of resins having different compositions, or may be printed or colored. . The stretching method is not particularly limited, but considering thermoformability, a method of sequential biaxial stretching or simultaneous biaxial stretching is preferable.

In the present invention, at least the inner fitting portion is 2
There is no limitation on the overall shape and size of the container body and the lid, provided that the axially stretched resin materials are in surface contact with each other. The shape of the inner fitting portion is arbitrary as long as the lid can be attached and detached, and the above-mentioned JP-A-9-32374 is also available.
It may be an inner fitting portion having any conventionally known shape as described in Japanese Patent Publication No. The material of the container body is also arbitrary, and various resin materials can be used. Considering the manufacturing cost, moldability, lightness, and appropriate rigidity, non-foamed or foamed resin sheet materials are preferable, and they may be a single layer, or the same or different materials may be laminated. May be.

The biaxially stretched resin material may be present in at least the inner fitting portion of the container. That is, the container main body is 10 to 100 over the entire surface of the foamed or non-foamed sheet that is the base material.
Thermoforming may be performed from a sheet in which a biaxially stretched film having a thickness of about μm is adhesively laminated, and at least the inner fitting portion is the same as that obtained by thermoforming from a base sheet in which the biaxially stretched film is not laminated. A biaxially stretched film may be post-bonded. Alternatively, it may be thermoformed from a biaxially stretched sheet having a thickness of about 100 to 500 μm. The same may be applied to the case of the lid, but the heat of the transparent biaxially stretched sheet or the sheet in which the transparent biaxially stretched film is laminated on the transparent non-foamed base sheet so that the contained food can be seen from the outside. It is preferably a molded product. The thickness of the base sheet is preferably about 0.1 to 5.0 mm.

As for the constitution of the sheet for molding the container body, a non-foamed polypropylene resin sheet containing a filler and a biaxially oriented polypropylene resin film laminated thereon, or a foamed polypropylene resin sheet made up of a biaxially oriented polypropylene resin film Laminated product, non-expanded polystyrene-based resin sheet containing a biaxially stretched polystyrene resin film laminated, expanded polystyrene-based resin sheet laminated with biaxially stretched polystyrene-based resin film, non-foamed polyethylene terephthalate resin A sheet in which a biaxially stretched polyethylene terephthalate resin film is laminated, a foamed polyethylene terephthalate resin sheet in which a biaxially stretched polyethylene terephthalate resin film is laminated, and the like are preferable. Among them, a laminated polypropylene resin sheet with a biaxially oriented polypropylene resin film is particularly preferable because it has excellent heat resistance, oil resistance, heat insulation, light weight, and beautiful appearance.

As a sheet for molding the lid, a biaxially stretched polystyrene resin sheet alone, a biaxially stretched polypropylene resin film laminated on a foamed polypropylene resin sheet, a biaxially stretched polypropylene resin sheet alone, a biaxial A laminate of a stretched polypropylene resin film and a non-stretched polypropylene resin sheet is preferable. Among them, the biaxially stretched polystyrene resin sheet alone is particularly preferable because it has strength when the lid is molded, has transparency to confirm the contents of the container, and is advantageous in terms of cost.

Further, when used as a range-up container, it has heat resistance capable of withstanding the range-up temperature, has heat insulation so that the container can be held with bare hands immediately after heating, and has a beautiful container appearance (glossiness, etc.). In consideration of the above, it is particularly preferable that the container body is formed of a laminated sheet of a foamed polypropylene-based resin sheet and a biaxially stretched polypropylene-based resin film, and the lid body is formed of a single biaxially-stretched polystyrene-based resin sheet.

Further, in the lidded container having the inner fitting portion according to the present invention, the inner fitting portion is hermetically sealed (difficult to leak water).
The quality depends on the frictional force (grip force) between the biaxially stretched resin materials that are in surface contact with each other. Then, the frictional force (grip force) is, for example, when one of the two biaxially stretched resin materials is fixed and the other is placed in a state in which water is present, and the whole is tilted, It can be grasped by the size of the angle (starting angle) at which the biaxially stretched resin material placed at 1 starts to slide. In the experiments conducted by the present inventor, the starting angle was 2
It has been found that when the angle is more than 0 °, sufficient sealing property (liquid leakage prevention property) can be secured.

Therefore, in the lidded container provided with the inner fitting portion according to the present invention, the biaxially stretched resin materials, which are in surface contact with each other, fix one of them and place the other in a freely movable state on the other, When water is present between the two, the physical properties of the other biaxially stretched resin material such that the other biaxially stretched resin material begins to slide on the one biaxially stretched resin material with an inclination angle (starting angle) exceeding 20 °. Having a value is a preferred embodiment.

[0019]

EXAMPLES The present invention will be described below with reference to examples. Example 1 First, a contact surface between biaxially stretched resin materials,
Also, by comparing the difference in frictional force (grip force) between the unstretched resin material and the biaxially stretched resin material on the contact surface, it was confirmed that the container according to the present invention is resistant to water leakage. The experiment is biaxially oriented polypropylene (OPP)
It was conducted between the film and the biaxially oriented polystyrene (OPS) sheet (invention) and between the unstretched polypropylene (CPP) film and the biaxially oriented polystyrene (OPS) sheet (comparative example). In addition, OPP film: biaxially oriented polypropylene film having a thickness of 30 μm (Toyobo Co., Ltd .: P-2161) CPP film: unstretched polypropylene film having a thickness of 30 μm (Toyobo Co., Ltd .: P1111) 250 μm biaxially stretched polystyrene sheet (Dainippon Ink and Chemicals Incorporated: SB-2
5) was used.

Measurement method: As shown in FIG. 1, a sheet 1 as a container body, here a foam layer (weighing 280 g / m ² ,
A biaxially stretched film (OPP film) or non-stretched film (CPP film) is laminated by heat fusion on a foamed polypropylene sheet in which a non-foamed layer (weighing 50 g / m ² , thickness 0.05 mm) is laminated on 0.8 mm thickness. The prepared sheet 1 is used as an iron board (200 mm x 300 mm) having a thickness of 5 mm.
mm) 2 sided tape (made by Solion Tech,
A plate-shaped board 3 adhered with a solion tape having a thickness of 10 μm) was manufactured.

75 mm × 75 mm (thickness 2 mm)
Sheet 5 to be a lid on one side of iron plate 4
A plate 6 in which an axially stretched sheet (OPS sheet) 5 is attached with a double-sided tape (made by Solion Tech, tape thickness 10 μm) is made, and the biaxially stretched resin material surfaces of the plate 6 and the plate board 3 are brought into contact with each other, 200, which is the weight of the iron plate 4.
The plate-like board 3 on which g was applied as a load was tilted, and the angle (starting angle) θ1 at which the plate 6 started sliding was measured. Further, 0.1 g of water was uniformly applied beforehand to the contact surfaces of the biaxially stretched resin materials of the plate 6 and the plate-like board 3, and the angle (starting degree) θ2 at which sliding started was measured in the same manner. The results are shown in Table 1.

[0022]

[Table 1]

As shown in Table 1, the starting angle between the CPP film and the OPS sheet, the OPP film and the OP
When the starting angle between the S sheet and the S sheet is compared, the starting angle between the OPP film and the OPS sheet is large both in the absence of water and in the presence of water. This indicates that the frictional force between the biaxially stretched resin materials is greater than the frictional force between the non-stretched resin material and the biaxially stretched resin material, especially when water is present. ing. That is, it can be seen that the contact surface between the biaxially stretched resin materials has a strong force for holding water (grip force).

[Embodiment 2] Next, a water leak test was conducted using a container with a lid which actually had an inner fitting portion. Using a normal thermoforming machine, the following four types of raw materials ~ 16 containers per shot, a container body having an inner fitting portion 11 having a shape shown in a perspective view in Fig. 2 and a sectional view in Fig. 3. 10 was thermoformed. In addition, 250 μm thick biaxially stretched polystyrene (O
PS) sheet (manufactured by Dainippon Ink and Chemicals, Inc .: SB
-25), a lid 30 having an inner fitting portion 31 having a shape shown in a perspective view in FIG. 2 and a sectional view in FIG.
Molded according to the specifications shown in. The dimensional variation of the container body 10 is shown in a) of the third embodiment. 80 cc of water was put into the container body 10 and the container body 10 was covered with the lid 30 and tilted at 90 ° for 90 seconds, and the water leakage state was confirmed. One shot (16 pieces) for water leakage test
I went about the minute. The results are shown in Table 2.

Raw material : The following base sheet 1 has the following O
A sheet obtained by laminating a PP film by heat fusion: a raw material : a sheet obtained by laminating the following OPP film at a base sheet 2 shown below by heat fusion: A raw material : a base sheet made at 1 below, a CPP film shown below Sheet laminated with the following: Raw material : Sheet obtained by laminating the following CPP film on the following base sheet 2 by heat fusion: Base sheet 1 : Basis weight 280 g / m ² , thickness 0.8 mm
Laminated with a non-foamed polypropylene sheet having a basis weight of 50 g / m ² and a thickness of 0.05 mm, and a base sheet 2 : a basis weight containing 30% filler 420
g / m ² , non-foamed polypropylene sheet with a thickness of 0.42 mm OPP film : biaxially oriented polypropylene film with a thickness of 30 μm (manufactured by Toyobo Co., Ltd .: P-2161) CPP film : unstretched polypropylene film with a thickness of 30 μm (Toyo Spinning Co., Ltd .: P1111)

[0026]

[Table 2]

As shown in Table 2, in the example products 1 and 2,
As a result of the biaxially stretched films being in surface contact with each other in the inner fitting portion of the container body and the lid body, there was no water leakage that would pose a problem in practical use in all 16 pieces, and the satisfactory results (leakage test The evaluation is ◎ or ○). However, in Comparative Products 1 and 2, one or two rejected products because the inner fitting portion between the container body and the lid is the contact surface between the unstretched film and the biaxially stretched film. (Water leak test evaluation is x)
Appeared.

[Embodiment 3] The variation in the size of the fitting portion per one shot (16 pieces) of the above-mentioned molded product was measured. The results are shown in Tables 3 and 4. a) Variability in container body size In Table 3, the dimension φA of the container body 10 is the dimension in the flow direction (MD direction) and the direction perpendicular to the flow direction (TD direction) for one shot (16 pieces) container. Is measured with a caliper. The measurement position is the portion of φA in the container cross-sectional views of FIGS. 2 and 3. Here, the flow direction (MD direction) is an extrusion direction when the raw material is manufactured by an extruder. MD is the TD direction
It is the direction perpendicular to the direction and the width direction of the raw material.

[0029]

[Table 3]

B) Measured Dimension of Lid Body As shown in Table 4, the dimension φB of the fitting portion of the lid body 30 is equal to that of the container body 10 in all of the example products 1 and 2 and the comparative example products 1 and 2. It was set to be 0.5 mm larger than the reference dimension φA. In each case, the reference dimension was an intermediate value between the maximum value (MAX) and the minimum value (MIN).

[0031]

[Table 4]

[Summary] As shown in Table 3, since the test data is the measured data per one shot (16 pieces) in the continuous forming, the elongation percentage of the sheet in the TD direction and the MD direction due to the heating during the forming. Change, and the shrinkage after molding of each molded product in one shot is different, which appears as dimensional variation. As can be seen from Table 3, the product 1 of Example has a larger variation per shot (1.46 mm and 1.28 mm) than the product 1 of Comparative Example, but in particular, the container body 10 of the product 1 of Example 1 Dimension φ
The maximum value (MAX) of A is φ166.55 mm, which is 0.25 m larger than φ166.3 mm of the dimension φB of the lid 30.
As shown in Table 2, water leakage is small in the product of the present invention (Example product 1), although it is large and there is a slight gap in the inner fitting portion between the container body 10 and the lid body 30. It is the result. The relationship between Example product 2 and Comparative example product 2 also shows the same tendency.

Conventionally, a container made of a biaxially stretched resin material has a residual stress due to the biaxially stretched resin material being stretched, so that the container is shrunk by heating during molding as compared with the unstretched resin material. It has been conventionally considered that it is not suitable for molding the inner fitting container, because the shrinkage ratio of the molded product per shot differs depending on the heating rate and the heating variation. However, a biaxially stretched resin material is used as the lid, and at least the inner fitting portion between the container body and the lid is so arranged that the biaxially stretched resin materials (in the above example, the OPP film and the OPS sheet) are in surface contact with each other. By doing so, it was found that the frictional force (grip force) there becomes large, and liquid leakage can be almost suppressed. Therefore, even if there is such dimensional variation in the molded product per shot, all are high. It becomes possible to use as a container with a lid that has a tight sealing property and is easy to attach and detach the lid, and as a result, it is possible to mold a container with a lid that has an inner fitting part using a foamed polypropylene resin sheet as a base material. Became possible.

[0034]

The lidded container provided with the inner fitting portion according to the present invention ensures easy sealing of the inner fitting portion between the container body and the lid body, and also makes it easy to attach and detach the lid body to and from the container body. It can be carried out. Therefore, it is extremely effective as a container for storing and selling foodstuffs containing a lot of liquid such as oden at the store. Further, since the dimensional difference of the fitting portion between the container body and the lid can be made larger than that of the conventional one, a material that easily causes dimensional variation among a large number of containers made in one shot is used. Even in this case, all of the molded products obtained continuously can be effectively used as a container.

[Brief description of drawings]

FIG. 1 illustrates an experiment conducted to compare the difference in frictional force (grip force) between the contact surface between biaxially stretched resin materials and the contact surface between a non-stretched resin material and a biaxially stretched resin material. Diagram for doing.

FIG. 2 is a perspective view showing a container body and a lid used when a water leakage test is performed using a container with a lid having an inner fitting portion.

FIG. 3 is a view showing a cross section of the container body and the lid shown in FIG.

[Explanation of symbols]

10 ... Container body, 11 ... Inner fitting portion of container body, 30 ... Lid body, 31 ... Inner fitting portion of lid body, θ ... Starting angle

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Norihisa Ohira             1226 Shimobemi, Sowa-machi, Sarushima-gun, Ibaraki Prefecture F term (reference) 3E033 AA10 BA16 BA22 BB08 CA19                       DA01 DA08 DD05 FA01                 3E067 AA03 AA11 AB01 BA10A                       BB14A BB16A BB17A BB18A                       BB25A BC07A CA30 EA18                       EA34 EB17 FA01 FC01 GD06                 3E084 AA12 AA24 AA25 AA26 AB10                       BA01 CA01 CC03 CC04 CC05                       DA01 DB09 DB13 DB18 DC03                       DC04 DC05 FA09 FC04 GA08                       GB12

Claims (6)

[Claims] 1. An inner fitting portion, which comprises a container body and a lid that can be attached to the container body, and an outer peripheral surface of the lid body is fitted inward with an inner peripheral surface of an opening of the container body. A lidded container having an inner fitting portion, wherein the biaxially stretched resin materials are in surface contact with each other at least in the inner fitting portion. 2. The container with a lid having an inner fitting portion according to claim 1, wherein the container body is a molded product formed from a sheet in which a biaxially stretched resin material is laminated on a base material sheet. 3. The container with a lid having an inner fitting portion according to claim 2, wherein the base material sheet is a foamed polypropylene resin sheet. 4. A container with a lid having an inner fitting portion according to claim 1, wherein the biaxially stretched resin materials that are in contact with each other are both biaxially stretched polypropylene resin films. 5. The inner fitting according to claim 1, wherein the biaxially stretched resin materials that are in contact with each other are one biaxially stretched polypropylene resin film and the other biaxially stretched polystyrene resin sheet. A container with a lid. 6. A biaxially stretched resin material, which is in surface contact with each other,
When one of them is fixed and the other is free to move on top of it, and when water exists between them, the other biaxially stretched resin material has an inclination angle (starting angle) of more than 20 °. The container with a lid having an inner fitting portion according to claim 1, which has a physical property value such that sliding starts on one of the biaxially stretched resin materials.