JPH0468228B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) This invention relates to a lid for a food storage container.

(Prior Art) Containers made of aluminum or synthetic resin are used to store and sell foods such as jam, butter, curry roux, etc. Such containers must be lightweight, hard to break, and capable of storing foods for a long period of time without deteriorating their quality. To that end, such containers were made of plastic or light alloys such as aluminum. Such a container is a food storage container according to the present invention.

A food storage container is composed of a container body and a lid. The lid must be airtightly joined to the container body and must be easily removable for use. To this end, the lid of a food storage container has been adhesively bonded to the container body so that a portion of the lid can be peeled off from the container body when necessary. A lid like this
This is a lid for a food storage container according to the present invention.

Attempts have been made to make the main body of a food storage container by laminating various plastic films together. However, in many cases, the lid was simply made of metal foil made of a light alloy such as aluminum. This is because the container body needs to be shaped to make it convenient for transportation, storage, and use, but the lid does not need to be shaped into such a shape and can be used as a flat film. . However, those using metal foil as the lid were not suitable as food containers because the general shape of the food could not be seen through the lid.

Therefore, an attempt was made to make the lid from plastic. However, making the lid from plastic is not easy. This is because not only is the lid required to have the same gas barrier properties as the container body, such as moisture permeability and oxygen permeability, but it also has various special requirements that are different from the container body. . In other words, the lid must have gas barrier properties, so it cannot be made from a single piece of plastic and must be made by laminating various plastics together. This is because when doing so, the bonded body constituting the lid may peel off in the middle, resulting in the inconvenience that the lid cannot be peeled off as a whole. In this way, when the lid is made of a laminated body, it is necessary to prevent the lid from peeling off in the middle, but it has been difficult to do so using materials with good gas barrier properties.

(Problems to be Solved by the Invention) The present invention seeks to provide a lid that overcomes the above-mentioned difficulties. In other words, it has good gas barrier properties, is suitable for long-term storage without causing food deterioration, and can be easily and airtightly bonded to the container body without peeling off at the middle layer of the lid. The purpose is to provide a lid that can be peeled off, which satisfies various seemingly contradictory requirements.

In this invention, an ethylene/vinyl alcohol copolymer film with good oxygen barrier properties is selected and used, but since this copolymer has the drawback of high water absorption, it is coated with polyolefin films on both sides. The idea is to reduce the water absorption of the ethylene/vinyl alcohol copolymer film and improve the gas barrier properties as a whole by bonding them together.

(Means for Solving the Problem) This invention provides a terpolymer film of ethylene/maleic anhydride/ethyl acrylate or a terpolymer film of ethylene/maleic anhydride/ethyl acrylate instead of the above-mentioned polyolefin film.
An ethyl acrylate binary copolymer film is bonded to the film to improve adhesion to the ethylene/vinyl alcohol copolymer film and prevent it from peeling off. In addition, since these films have poor strength, a stretched polypropylene film or stretched polyester film is further bonded to the film to improve the overall strength, so that it can be used as a lid without tearing easily. I tried to avoid it. Further, the above-mentioned stretched film is printed or metal-deposited to reduce the transmission of light and prevent deterioration of the food, and also to give it a beautiful appearance and increase its commercial value as a lid.

This invention involves laminating a ternary copolymer film of ethylene, maleic anhydride, and ethyl acrylate on one side of an ethylene/vinyl alcohol copolymer film, and then printing or metal vapor-depositing oriented polypropylene or oriented For food storage, made by laminating polyester films together, laminating an ethylene/ethyl acrylate copolymer film or the above terpolymer film on the other side of the above copolymer film, and adhering a sealant thereon. It provides a lid for the container.

(Example) An example of the lid of the food storage container according to the present invention will be described below based on the drawings. FIG. 1 is an enlarged partially cutaway sectional view of the lid of the food storage container according to the present invention. FIG. 2 is a perspective view showing the state in which the food storage container lid according to the present invention is used.

In FIG. 1, 1 is a stretched polypropylene film or a stretched polyester film, 2 is a layer of printing ink or a layer of aluminum vapor-deposited film to which the printing ink has been applied, and 3 is a layer of ethylene/maleic anhydride. A terpolymer film of ethyl acrylate, 4 is an ethylene/vinyl alcohol copolymer film, 5 is an ethylene/ethyl acrylate copolymer film or the above terpolymer film, and 6 is an ethylene/ethyl acrylate copolymer film. A layer of sealant.

A food storage container lid such as that shown in FIG. 1 is used in the manner shown in FIG. Second
In the figure, A is the lid A shown in Figure 1, and B
is the main body of the food storage container, and C is the knob. The main body B has a bottom and a side wall, the upper end of the side wall is folded back to the outside, and the folded part forms a plane substantially parallel to the bottom, forming a flat frame-shaped part. . The lid according to the present invention is superimposed on this frame-shaped portion, and is bonded to the main body by bringing the sealant 6 into contact with the frame-shaped portion. however,
The knob C is not glued and the lid can be peeled off from this part.

(Function) The lid according to the present invention is made of ethylene-vinyl alcohol copolymer film (hereinafter referred to as EVOH).
Since this material is used, the oxygen permeability and moisture permeability are low, and the so-called gas barrier properties are good.
EVOH has the disadvantage that it has somewhat high water absorption, but in this invention, one side of EVOH is coated with ethylene.
Since a terpolymer film of maleic anhydride and ethyl acrylate (hereinafter referred to as terpolymer) is used, this suppresses the water absorption of EVOH, and therefore the water absorption as a whole is also small. It has good gas barrier properties. Furthermore, since the terpolymer contains maleic anhydride and ethyl acrylate, it has strong adhesion to EVOH and various other synthetic resins, and therefore has a strong adhesion to EVOH and various other synthetic resins, and therefore is suitable for use in printing ink layers or vapor-deposited metals such as aluminum metal. Adheres strongly to surfaces.

In addition, since an ethylene/ethyl acrylate copolymer film (hereinafter referred to as EAE) or a terpolymer is bonded to the other side of the EVOH, this EAE or terpolymer also strongly adheres to the EVOH. This will suppress the water absorption of EVOH.
Further, since a sealant, that is, an airtight adhesive is applied thereon, the lid is strongly and airtightly adhered to the container body by the sealant.

(Effects of the Invention) Thus, the lid according to the present invention is made of a laminated body of various synthetic resin films, and has excellent gas barrier properties as a whole, so that gas and moisture are prevented from entering through the lid. As a result, food is less likely to deteriorate in quality, making it suitable as a lid for food containers. Although this lid is a laminated body, the films that make it up are strongly adhered, so even if you forcibly peel it off after adhering it to the container body with a sealant, the lid will remain intact. The sealant is peeled off from the container body at the sealant without being peeled off inside, so the lid can be removed reliably and easily. Furthermore, since this lid uses stretched polypropylene or polyester film on its surface, it is strong and will not easily tear even if subjected to impact during use.
Moreover, it is convenient for printing and forming metal vapor deposition films, and various designs can be applied to make it beautiful. The lid according to the invention provides these advantages.

As EVOH, for example, films sold under the names of Soarnol from Nippon Gosei and EVAL from Kuraray Co., Ltd. can be used. This film is said to be a copolymer of 30% ethylene and 70% vinyl alcohol. As EVOH
Used as a thickness of 10 to 30 microns.

As the terpolymer, for example, one sold under the name Bondine by Sumika CF Co., Ltd. can be used. It is said to have a composition of about 5 to 30% by weight maleic anhydride and ethyl acrylate, with the balance being ethylene. Suitably, the terpolymer has a thickness of 5 to 30 microns.

Stretched polypropylene or polyester films are used with a thickness of 12 to 50 microns. Among these, polyester film is a film made of a compound produced by ester bonding of ethylene glycol and terephthalic acid.

EAE is a copolymer containing 5 to 20% by weight of ethyl acrylate and the balance being ethylene. As the EAE, for example, one available from Mitsubishi Yuka Co., Ltd. under the name of Modelix can be used. EAE is used in thicknesses of 5 to 30 microns.

As a sealant, for example, from Mitsubishi Yuka Co., Ltd.
What is sold under the name of VMX can be used. VMX can be used in thicknesses of 5 to 30 microns.

The lid according to the present invention can be made all at once by putting each synthetic resin into separate extruders and molding them into an integrated laminated film in one die. Therefore, this lid has the advantage of being easy to manufacture. Additionally, since this lid is made of synthetic resin, it wrinkles less during handling, does not break, and is easier to cut than conventional aluminum foil lids. It also has the advantage of Therefore, the lid according to the present invention is extremely convenient in practice.

[Brief explanation of the drawing]

FIG. 1 is an enlarged partially cutaway sectional view of the lid of the food storage container according to the present invention. FIG. 2 is a perspective view of a container in which the food storage container lid according to the present invention is used. In the figure, 1 is a stretched polypropylene or polyester film, 2 is a layer of printing ink or a layer of aluminum vapor-deposited film with printing ink attached, and 3 is a terpolymer film of ethylene, maleic anhydride, and ethyl acrylate. , 4 is ethylene.
A vinyl alcohol copolymer film, 5 an ethylene/ethyl acrylate copolymer film or a terpolymer film, and 6 a sealant layer.

Claims (1)

[Claims] 1 A terpolymer copolymer film of ethylene, maleic anhydride, and ethyl acrylate is laminated on one side of an ethylene/vinyl alcohol copolymer film, and then a stretched polypropylene or stretched polyester film printed or metal-deposited on top of that. A lid for a food storage container, which is obtained by laminating an ethylene/ethyl acrylate copolymer film or the terpolymer film described above on the other side of the copolymer film, and applying a sealant thereon.