JPH0314350Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention is a lid for sealing the open end of a container having a cylindrical body made of paper, metal foil, plastic, etc., or a laminate thereof. It is related to materials.

[Conventional technology]

Instead of a container such as a metal can or a glass bottle, for example, as shown in FIG. BACKGROUND ART In recent years, packaging containers of the type in which the upper and lower open ends are sealed with lid members 2 have been used, and are used not only for solid items such as confectionery, but also for packaging various liquids such as juice, milk, and edible oil.

Various configurations can be considered as a lid material for sealing the open end of this type of container, but in order to completely seal the contents, the opening end of the cylindrical body 1 as shown in FIG. The lid material 2 is fitted into the open end so that the edge portion is held between the front and back surfaces of the lid material 2 by the peripheral edge of the lid material 2, and the overlapping portion of the lid material 2 and the cylindrical body 1 is heat-sealed. The lid material is mainly used.

[Problem that the invention attempts to solve]

Therefore, in order to easily fit this type of lid material into the open end of the cylindrical body, the peripheral edge is first formed into a square-shaped cross section as shown in FIG. It is attached to the open end and heat sealed.

The lid is usually formed by cold forming, which also includes punching, and conventionally, as shown in Figure 8, aluminum foil 11 with a thickness of about 100 to 140 μ is used to form the lid into a predetermined shape by press forming. Resin coating film 12 having chemical resistance, abrasion resistance, etc. such as epoxy resin on the surface of
A polyolefin coating 13 having a thickness of 60 to 80 microns was laminated on the back surface of the polyolefin film 13, which was formed to have a thickness of 3 to 6 microns. In this conventional lid material, the thickness of the aluminum foil is reduced to reduce cost and weight.
It has the drawbacks of reduced strength, poor moldability, and poor shape retention after molding.

[Means for solving problems]

The present invention is intended to solve the above-mentioned conventional problems, and uses acrylonitrile/butadiene-modified acrylonitrile/acrylic acid ester containing 50% or more (by weight, same hereinafter) of polyacrylonitrile as a lid material for a cylindrical container. It is an object of the present invention to provide a lid material for a packaging container, which is made by sequentially laminating metal foil and polyolefin film on the lower surface of a polymeric resin sheet.

[Effect]

In the present invention, the sheet of acrylonitrile/acrylic acid ester copolymer resin (hereinafter referred to as AN/AE copolymer resin) is used because it has moldability and barrier properties. The thickness of the sheet is
It is selected appropriately depending on the purpose, but usually 100 to 250μ
Those within the range of are used. Preferably it is 150μ thick. The AN/AE copolymer resin that forms the sheet is modified with acrylonitrile-butadiene rubber (NBR), which contains at least 50% polyacrylonitrile. The content of butadiene rubber is preferably 5 to 40%.

In the present invention, the metal foil is used for purposes such as barrier properties, and has a thickness of 20 to 60μ, preferably 40μ.
A certain degree is used. As the metal foil, aluminum foil is usually preferred.

The polyolefin film is provided for the same purposes as conventional ones, that is, to impart heat sealability (thermal adhesion) and corrosion resistance to the contents. The thickness is about 60 to 80μ, similar to conventional ones.

〔Example〕

FIG. 4 is an enlarged sectional view showing one embodiment of the lid material of the present invention, in which 22 is an AN/AE copolymer resin sheet;
21 indicates aluminum foil, and 23 indicates polyolefin film.

FIG. 5 shows an example in which a printed layer 24 is provided on the surface of the lid material having the structure shown in FIG. 4, and FIG. 6 shows an example in which a paper 25 is laminated instead of the printed layer 24. It goes without saying that the paper 25 in FIG. 6 may be printed or colored.

Since the lid material of the present invention has an AN/AE copolymer resin sheet 22 formed on its surface, for example, as shown in FIG. You can also create an opening and seal it.

[Effect of idea]

Since the lid material of this invention uses an AN/AE copolymer resin sheet as its main component, it is thinner and lighter than conventional metal foils such as aluminum foil. Also, this AN・AE
Copolymer resins have excellent barrier properties and heat resistance, so they have the advantage of being able to withstand hot-back or boil sterilization. Furthermore, since the sheet is made of resin, it is possible to heat-bond a pull tab, etc. as shown in Figure 7 above, and it can be easily incinerated after the container has been used, and the amount left in the incineration can be reduced. It has advantages such as less In addition, conventional lid materials have been limited to heat sealing by external heating and pressure bonding using conventionally used heating plates, but according to the lid material of the present invention,
Because the metal foil is thin and the resin sheet is thick, it can be heat-sealed using high-frequency induction heating, so it can be faster than conventional lid materials, has good moldability, and is inexpensive, so it is expected to streamline production. It also has effects such as being able to do things.

[Brief explanation of the drawing]

Figure 1 is a perspective view of a container using the lid material of the present invention;
Fig. 2 is a sectional view taken along the - line in Fig. 1, Fig. 3 is a schematic sectional view of the lid, Figs. A perspective view showing an example in which a pull tab is provided, and FIG. 8 is an enlarged sectional view of a conventional lid material. In the figure, 1... cylindrical body, 2... lid material, 3... pull tab, 21... aluminum foil, 22... AN/AE copolymer resin sheet, 23... polyolefin film.

Claims (1)

[Scope of Claim for Utility Model Registration] The open end of a cylindrical body made of paper, metal foil, plastic, etc. or a laminate thereof is fitted and the overlapping portion is heat sealed to close the open end. A packaging container, which is a lid material for a packaging container, characterized in that metal foil and polyolefin film are sequentially laminated on the lower surface of a sheet of acrylonitrile butadiene-modified acrylonitrile acrylate copolymer resin containing 50% or more of polyacrylonitrile. lid material.