JP2521613Y2 - Container lid - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a lid for a container, and more particularly to a lid suitable for a container for storing food to be heated together with a container in a microwave oven.

[Conventional technology]

BACKGROUND ART When a food packaged with a synthetic resin film or a film using a metal foil is heated in a microwave oven, various methods have been conventionally used to prevent an increase in internal pressure in the package due to steam generated during cooking. For example, in the case of a tray type container that stores cooked rice etc.
When cooking the microwave, the lid on the container is partly peeled off, and some holes are opened with a toothpick.

[Problems to be solved by the device]

However, in the case where the lid of the microwave food container is partly peeled off, the amount of water evaporated from this part is large, which causes uneven cooking. In addition, a tool for that purpose is required to open a hole in the lid, and if the opening method is insufficient, there is a risk that the pressure in the container rises during cooking and the container bursts.

Furthermore, there is variation in the cooking completion time depending on the microwave oven model, the state of the atmosphere during cooking, the state of the food before cooking, etc. Even if you cook for the same time, the same finish will not result due to the variation. There is.

Therefore, the present invention provides a lid for a container that is suitable for a lid of a container that stores food heated in a microwave oven, can form a vent hole automatically with heating, and can obtain an optimum cooking state. Is intended.

[Means for solving the problem]

In order to achieve the above-mentioned object, the present invention is a container having a top plate portion that covers the opening portion of the container, and a fitting portion that is formed on the outer periphery of the top plate portion and that fits into the opening flange portion of the container. In the lid, an opening is formed in the top plate portion, and a laminated film covering the opening is attached to the outer surface of the top plate portion, and the laminated film is attached to the top plate portion, It is characterized in that it is formed of a perforated film having a large number of vent holes and a heat-shrinkable film releasably laminated on the perforated film.

[Action]

When the container lid configured as described above is heated in a state of being covered with a container for storing microwave-heated food, the heat-shrinkable film shrinks and peels from the perforated film due to the temperature rise due to heating, and the perforated film passes through. Pores open.

〔Example〕

The present invention will be described below based on an embodiment shown in the drawings.

FIG. 1 is a sectional view showing a state in which the container lid of the present invention is fitted to the container, FIG. 2 is a sectional view showing a laminated film suitable for being stuck to the opening of the lid, and FIG. 3 is It is sectional drawing which shows the state which the heat-shrinkable film shrunk.

The container lid 1 of the present invention includes a top plate portion 1a that covers the opening 2a of the container 2 and a fitting portion 1b that is formed on the outer periphery of the top plate portion 1a and that fits into the opening flange portion 2b of the container 2. And has a top plate 1a
For example, the opening 1c is formed in the central part, and the laminated film 3 covering the opening 1c is attached to the outer surface of the top plate 1a. The laminated film 3 is formed of a perforated film 4 attached to the top plate portion 1a and a heat-shrinkable film 5 releasably laminated on the perforated film 4, and the perforated film 4 has an appropriate ventilation hole. It has many 4a.

The container lid 1 can be formed of various materials, but is made of, for example, polypropylene, polyethylene terephthalate, or another heat-resistant synthetic material because of its heat resistance to heat, adhesiveness with the perforated film 4, and ease of manufacture. It is preferably formed of resin.

Further, the container lid 1 is provided with a fitting portion 1b that can be fitted into the opening flange portion 2b of the container 2 and a top plate portion 1a on which an appropriate shape, area, and number of opening portions 1c are formed. Opening of plate 1a
As long as the laminated film 3 has a sticking portion around 1c, it can be manufactured in any shape. The opening 1c
May have a relatively large diameter at one place, but may have a relatively small diameter at one to several places.

As the heat-shrinkable film 5, a film having a shrinkage rate of 10% or more in 10 seconds of hot water immersion at 90 to 100 ° C., preferably a film having a barrier property, for example, a coextrusion composite stretched film is used. However, a material having an appropriate shrinkage ratio can be used depending on the usage condition, the heating temperature of the food, the usage area, and the like. The thickness is not particularly limited, but a range of 5 to 300 μ, preferably 20 to 100 μ is suitable from the viewpoint of cost strength.

Specific examples of the heat-shrinkable film 5 include polyvinyl chloride, polypropylene, styrene-butadiene copolymer, polyethylene terephthalate, polystyrene,
Nylon and the like can be mentioned, and these uniaxially or biaxially stretched films, or those obtained by laminating these heat-shrinkable films with other films having barrier properties can be used.

In particular, the heat-shrinkable film 5 is used to control the peeling direction of the film by using an uneven heat-shrinkable film, that is, a film having a heat shrinkage in one direction larger than that in the direction orthogonal to the film. It is possible to improve the appearance at the time of peeling. Such a heat-shrinkable film can be obtained by adjusting the stretching direction of the film or by laminating films having different heat shrinkages.

On the other hand, the perforated film 4 has heat resistance, non-heat shrinkage or low heat shrinkability, and also has ventilation holes 4a having an appropriate diameter and spacing.
It is possible to use various films, non-woven fabrics, or the like to which air permeability is imparted. Various materials can be used as the material of the perforated film 4, and, for example, polyethylene, polypropylene, ethylene vinyl acetate copolymer, or those obtained by laminating an easily peelable agent layer can be used. This perforated film 4 has a thickness of 15 to 10
0μ, the diameter of vent hole 4a is about 0.1 to 3 mm, and the interval is 0.5 to 20 mm
It is preferably about the same.

By sticking such a perforated film 4 around the opening 1c on the outer surface of the top plate 1a so as to cover the opening 1c, it becomes possible to control the air permeability when the heat-shrinkable film 5 is peeled off. , Forming a relatively large opening 1c in the container lid 1,
By using such a perforated film 4, it becomes easy to impart appropriate air permeability to the entire top plate portion 1a of the container lid 1. As a result, it is possible to prevent cooking unevenness due to water evaporation from a part of the container lid 1.

The perforated film 4 and the heat-shrinkable film 5 need to be laminated with an adhesive strength such that they can be separated when the heat-shrinkable film 5 is shrunk. By subjecting one side to corona discharge treatment and then thermocompression-bonding, the adhesive strength at the interface between both films 4 and 5 is in an appropriate range, for example, 5-250 g / 20 mm width (20 ° C,
The pulling speed can be adjusted to 200 mm / min and 180 ° peeling). Further, as shown in FIG. 2, when another film 51 such as a barrier film or a protective film having a high strength at room temperature is laminated on the outer layer of the heat-shrinkable film 5 to form a multilayer structure, The adhesive layer 52 is provided on and laminated.
It is preferable to increase the adhesive strength between the heat-shrinkable film 5 and the outer layer film 51 to prevent the outer layer film 51 from peeling off before use to maintain a predetermined barrier property and protective ability.

Further, the lamination film 3 and the container lid 1 can be bonded to each other by general heat sealing or an adhesive.

The container lid of the present invention can be used as a lid for packaging food-filled containers, but when cooking microwave-heated food packaged with another barrier packaging material,
It is also possible to fit the opening flange portion of the container after removing the packaging material and use it only for cooking. As described above, by using the container lid of the present invention only for heating and cooking, and by using another heat-resistant packaging material in the manufacturing process, heat sterilization such as retort sterilization can be performed.

Example 1 Uniaxially stretched polyvinyl chloride film / (adhesive layer) / heat-shrinkable multilayer film (ethylene vinyl acetate copolymer / saponified ethylene vinyl acetate copolymer / nylon resin / ethylene vinyl acetate copolymer) / Yes A laminated film composed of a perforated polypropylene film was heat-sealed so as to cover the entire surface of an opening having a diameter of 40 mm provided in the central portion of the top plate of a container lid of polypropylene alone having a size of 147 mm × 114 mm. The heat-shrinkable multi-layer film and the perforated polypropylene film were subjected to thermocompression bonding after the corona discharge treatment at the interface between both films, and the adhesive strength at the interface between them was 70%.
g / 20mm width (tensile strength 200mm / min, 180 ° peeling).

Cover the lid of this container with shrimp pilaf 20 of commercial retort food.
Cover with a container filled with 0g, microwave oven (Matsushita Electric Industrial
NE-M330 type, rated high frequency output 500W) and heated at output 500W for 3 minutes, uniaxially stretched polyvinyl chloride film / heat-shrinkable multilayer film heat sealed to the opening of the container lid The heat-shrinkable base film made of a film shrank, peeled from the perforated film, and curled on the outer roll (see FIG. 3). At that time, steam was appropriately blown out from the vent holes of the perforated film, and shrimp pilaf with good texture without heating unevenness could be produced.

Example 2 Diameter 30 mm formed at the center of the top plate of the lid for a container with a diameter of 98 mm
The same laminated film as in Example 1 was heat-sealed into the opening of the above. The container lid was put on a polypropylene round container having a container opening diameter of 88 mm (collar outer diameter of 98 mm) filled with 180 g of potage soup of retort food, and Example 1
Heated in microwave as well. The heat-shrinkable base film contracted and peeled when heated for about 2 minutes and 30 seconds, so when the heating was stopped there, the soup was cooked in a good texture.

[Effect of device]

As described above, in the container lid of the present invention, the opening is formed in the top plate portion that covers the opening portion of the container, and the laminated film that covers the opening is attached to the outer surface of the top plate portion. The laminated film is formed by a perforated film having a large number of vent holes, which is attached to the top plate portion, and a heat-shrinkable film releasably laminated on the perforated film. When it is covered with a container containing heated food and heated in a microwave oven, the heat-shrinkable film shrinks and peels from the perforated film when the temperature rises appropriately, and the vent holes of the perforated film open.

Therefore, no piercing tools are needed and there is no rupture or spillage. Moreover, when the heat-shrinkable film is peeled off from the perforated film, the ventilation holes of the perforated film are opened, whereby the air permeability can be controlled, and uniform heat cooking can be performed. Further, it is possible to know the proper cooking state by shrinking and peeling the heat-shrinkable film, and it is possible to obtain a stable finished state.

[Brief description of drawings]

FIG. 1 is a sectional view showing a state in which the container lid of the present invention is fitted to the container, FIG. 2 is a sectional view showing a laminated film suitable for being attached to the opening of the container lid, and FIG. The figure is a cross-sectional view showing a state in which the heat-shrinkable film is shrunk. 1 ... Lid for container, 1a ... Top plate part, 1b ... Fitting part, 1c ...
… Aperture, 2 …… Container, 2a …… Aperture of Container 2, 2b ……
Opening collar of container 2, 3 ... laminated film, 4 ... perforated film, 4a ... vent hole, 5 ... heat-shrinkable film

Claims (1)

(57) [Scope of utility model registration request] 1. A container lid having a top plate portion for covering an opening portion of the container and a fitting portion formed on an outer periphery of the top plate portion and fitted into an opening flange portion of the container, wherein the top plate portion. A perforated hole having a large number of vent holes, which is formed with an opening, and a laminated film covering the opening is attached to the outer surface of the top plate portion, and the laminated film is attached to the top plate portion. A lid for a container, which is formed of a film and a heat-shrinkable film releasably laminated on the perforated film.