JPS6028582Y2 - Thin wall metal containers for retort food - Google Patents

Description

[Detailed description of the invention] This invention is a lightweight and inexpensive gas barrier whose container body is a molded body of a laminated material of extremely thin metal foil and heat-resistant resin film.
The present invention relates to a sealed retort container with excellent properties.

Currently, retort food containers include cans, bottles, aluminum foil laminated material molded containers, and heat-resistant resin molded containers, but each has the following drawbacks.

Tin cans are mainly used as canning containers, but because they are thick and heavy, they are expensive and difficult to dispose of.

In addition, the bottles used for bottled foods are heavy and bulky, which poses transportation problems and disposal difficulties.

Recently, there have been molded and sealed containers made of aluminum foil laminates whose inner surfaces are made of heat-fusible resin, but the aluminum foil used in these containers is still thick and costs have not been sufficiently reduced.

Recently, there have been plastic containers made only of heat-resistant resin, such as so-called transparent containers, but they have problems in terms of gas barrier properties.

An object of the present invention is to provide a sealed container for retort food that is lightweight, inexpensive, and has excellent gas barrier properties.

The present invention will be explained in detail below.

The figure is a sectional view of a sealed container that is an embodiment of the present invention.

The retort food sealed container 11 according to the present invention has a thickness of 9 to 3
An outer layer 1 made of a heat-resistant thermoplastic resin film with a thickness of 0μ and an intermediate layer 2 of a metal foil with a thickness of 30 to 60μ are laminated via an adhesive layer 4.
The inner layer 3 made of a heat-sealable heat-sealable thermoplastic resin film of 0 μm is laminated with an adhesive layer 4 interposed therebetween, and a laminated material is cold-formed.

As the outer layer 1, polyester, polycarbonate, nylon, polypropylene, etc. can be used.

A printed layer of ink 5 is provided on one side of this heat-resistant thermoplastic resin film to be printed.

This outer layer 1 is necessary to impart cold formability to the laminated material, and also prevents pinholes from forming during retort sterilization.

Next, as the intermediate layer 2, a metal foil having a thickness of 30 to 60 μm is used, and aluminum foil is preferable from the viewpoint of weight reduction.

Among these, soft aluminum that exhibits a good elongation rate is preferred.

If the thickness is less than 30 μm, a sufficient molding depth cannot be obtained and pinholes are generated at some corners during molding, resulting in loss of barrier properties and causing problems in food preservation.

Furthermore, the rigidity of the laminated material is low, making it difficult to obtain a good shape as a container.

If it is thicker than 60 μm, the purpose of reducing weight and cost is lost.

Next, as the inner layer 3, polyethylene, polypropylene, polyamide, polyester ether resin, and copolymer resins thereof can be used.

The lid material 12 consists of an outer layer 6 of a printed heat-resistant thermoplastic resin film, an intermediate layer 7 of metal foil, and an inner layer 8 of a heat-sealable thermoplastic resin film, and the film thickness of the outer layer 6 and inner layer 8 is equal to that of the container. The same range as the main body is preferable, but since the metal foil of the intermediate layer 7 does not need to be molded, the thickness may be 7 to 20 μm.

Each layer of the main body and lid material can be bonded using an incyanate adhesive, an epoxy adhesive, or the like.

The molding is cold working, and drawing, bulging bottom pressure forming, etc., or a combination thereof can be used.

As detailed above, the thin-walled metal container for retort food of the present invention is made by laminating a heat-resistant thermoplastic resin film of 9 to 30 μm and a metal foil of 30 to 60 μm in thickness, and then applying heat to the other side of the metal foil. A retort is made by cold-forming a laminated material made by laminating a heat-sealable heat-resistant thermoplastic resin film and further laminating a heat-sealable heat-sealable thermoplastic resin film on the other side of the metal foil. It has the advantages of having sufficient strength to withstand sterilization, being lightweight, having excellent gas barrier properties, and being inexpensive.

Next, the present invention will be specifically explained by giving examples.

Example 1 A printed biaxially oriented polypropylene film with a thickness of 20 μm, a soft aluminum foil with a thickness of 40 μm, and an unstretched polypropylene film with a thickness of 60 μm were placed in this order using an incyanate adhesive so that the printed surface adhered to the aluminum surface. The opening size is 120 x 16 by making a laminated material that is glued together and using stretch molding.
0711171 depth 24711111 flange width 1-
I got the body of.

This container was filled with food and the lid material was heat-sealed to produce a sealed container.

The lid material was a laminate made of printed polyester film with a thickness of 12 μm, aluminum foil with a thickness of 9 μm, and unstretched polypropylene with a thickness of 60 μm adhered in this order with an isocyanate adhesive so that the printed surface adhered to the aluminum surface. used.

This sealed container was subjected to 6-powder retort sterilization at 125°C, but no abnormalities were observed.

Example 2 A printed unstretched nylon film with a thickness of 20μ, a soft aluminum foil with a thickness of 40μ, and an unstretched polypropylene with a thickness of 60μ were adhered in this order using an isocyanate adhesive so that the printed surface adhered to the aluminum foil. We made a laminated material and used stretch molding to make the upper opening dimension 120x16 and the depth of erosion 27rIr! A main body with n flange width l- was obtained.

This container body was filled with food, and a lid material similar to that in Example 1 was heat-sealed to prepare a sealed container, and retort sterilization was performed under the same conditions, but no abnormalities were observed.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a sealed container that is an embodiment of the present invention. 11... Container body, 12... Lid, 1,
6...Heat-resistant thermoplastic resin film, 2,7.
... Metal foil, 3.8 ... Heat-sealable heat-resistant thermoplastic resin film, 4 ... Ink, 5
······glue.

Claims (1)

[Scope of utility model registration request] Heat-resistant thermoplastic resin film with a thickness of 9 to 30μ and a thickness of 3
A container body is made by cold-forming a laminated material made by laminating a metal foil of 0 to 60μ and further laminating a heat-sealable heat-resistant thermoplastic resin film of 50 to 100μ on the other side of the metal foil. A retort food container.