JP2009286433A - Sealed metal container not requiring sealing compound in seamed section - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To inexpensively provide a seamed sealed metal container by eliminating management, material and machining costs for applying a sealing compound. <P>SOLUTION: This sealed metal container not requiring a sealing compound in a seamed section has a cover 2 on a container body 1 with a bottom and is sealed by double-seaming. Polypropylene films 34 are joined to cover the inside and outside faces of the body 1. The thickness of the inside film is 3,200 &mu;m and that of the outside film is 4,100 &mu;m. The seamed part 5 has the outside face film 4 tightly adhered between both faces of the inside wall 7a of a U-shaped part 7 formed by folding the top end peripheral edge of the cover 2 and the inside faces of both walls 6a, 6b of an inverted U-shaped part 6 formed by folding the top end peripheral edge of the body 1 and the inside film 3 tightly adhered between both faces of the inside wall 6a of the inverted U-shaped part 6 of the cover 2 and the inside face of the outside wall 7b of the U-shaped part 7 of the body 1. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a hermetic metal container that does not require a sealing compound in a tightening portion in a metal container having a tightening portion such as a food can.

A sealed metal container formed by covering and tightening at least the top of the top and bottom of a conventional container body is simply a metal container body and a metal lid on which a resin coating is applied for the purpose of imparting corrosion resistance. As the contents are sealed in a sealed metal container, there is a concern that the contents may leak from the tightened portion. To prevent this, as disclosed in the following publication: A rubber-based resin called a sealing compound, which is a sealing material for tightening, is annularly applied to the inner surface corresponding to the winding portion of the metal lid member before tightening.
JP 2000-15373 A JP 2001-278326 A

  Since application of the sealing compound requires strict control of the application amount, application uniformity, application position, and the like, the contents may leak if any of these is missing. Moreover, since the material cost and processing cost of a sealing compound are required, this has also contributed to the cost increase of the winding metal container.

  An object of the present invention is to provide a hermetically sealed metal container that eliminates the need for a sealing compound at the tightening portion in order to eliminate the above problem.

  According to the first aspect of the present invention, there is provided a sealed metal container that does not require a sealing compound in the tightening portion. The sealed metal container is formed by covering and tightening at least one of the top and bottom portions of the container body. A synthetic resin film having a thickness of 10 to 500 μm is bonded and coated on at least one of the surfaces.

  The invention of claim 2 is a hermetically sealed metal container that does not require a sealing compound in the tightening portion of claim 1, wherein the inner synthetic resin film is made of polypropylene or polyethylene, and the outer synthetic resin film is made of polypropylene. To do.

  According to a third aspect of the present invention, there is provided a hermetically sealed metal container that does not require a sealing compound at the tightening portion, and is a hermetically sealed metal container in which at least the top portion of the top and bottom portions of the container body is covered and tightened. A synthetic resin film having a thickness of 10 to 500 μm is bonded and coated.

  According to a fourth aspect of the present invention, in the sealed metal container in which the sealing compound is not required for the tightening portion according to the first aspect, the synthetic resin film is made of polypropylene or polyethylene.

  In the above, as a metal used for a container trunk | drum and a lid | cover, aluminum is preferable, and when using aluminum, the thickness needs 50-300 micrometers, and 80-150 micrometers is preferable among these. If the thickness is less than 50 μm, the strength is insufficient, so that winding is difficult, and if it exceeds 300 μm, the cost increases.

  In the first aspect of the invention, the thickness of the synthetic resin film coated on at least one of the inner and outer surfaces of the container body is limited to 10 to 500 μm because the thickness is less than 10 μm. This is because if the thickness exceeds 500 μm, the cost increases, and the preferred thickness is 50 to 200 μm.

  In the invention of claim 2 and claim 4, the reason why polypropylene or polyethylene is used for the synthetic resin film on the inner surface of the container body and the lid is to provide corrosion resistance and heat resistance during heat sterilization. In the invention of claim 2, the reason why polypropylene is used for the synthetic resin film on the outer surface of the container body is to provide heat resistance during heat sterilization.

  In the invention of claim 3, the thickness of the synthetic resin film on the inner surface of the lid is limited to 10 to 500 μm because the sealing property cannot be maintained when the thickness is less than 10 μm, and the cost is increased when the thickness exceeds 500 μm. The preferred thickness is 50 to 200 μm.

  As the adhesive used for joining the synthetic resin film, an adhesive having heat resistance during heat sterilization is used.

  According to the hermetically sealed metal container that does not require a sealing compound in the tightening portion of the present invention, the coating amount, coating uniformity, and coating position required for applying the sealing compound as a sealing material for winding that has been conventionally used This eliminates the need for strict management such as the above, and eliminates the material cost and processing cost of the sealing compound, so that the sealed metal container can be provided at low cost.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 shows a main part of a sealed aluminum container in which a sealing compound is not required for a tightening part according to the present invention. A lid (2) is put on a bottomed container body (1) and double-tightening is performed. It is hermetically sealed. Polypropylene films (3) and (4) are bonded and coated on both the inner and outer surfaces of the container body (1). The inner polypropylene film (3) has a thickness of 200 μm and the outer polypropylene film (4) has a thickness of 100 μm. In the tightening portion (5), the inner surfaces of both walls (6a) and (6b) of the inverted U-shaped portion (6) formed by bending the upper end periphery of the container body (1) and the upper end periphery of the lid (2) The outer polypropylene film (4) is in close contact between both sides of the inner wall (7a) of the U-shaped part (7) formed by bending the outer wall of the U-shaped part (7) of the container body (1) ( 7b) The inner surface polypropylene film (3) is in close contact between the inner surface and both inner walls (6a) of the inverted U-shaped part (6) of the lid (2).

  In the above embodiment, the polypropylene film is bonded and coated on both the inside and outside of the container body, but it may be coated on only one of the both surfaces instead of the both surfaces. However, it is more reliable to prevent contents from leaking when coated on both sides. Moreover, when covering only one of the two surfaces, it is preferable to cover the inner surface. Furthermore, when a polypropylene film is bonded to the inner surface of the lid, there is no need to dare to cover the container body with the polypropylene film.

The lid (2) has a circular opening (9) having an upward curled edge (8) around it, and the circular opening (9) is closed from above with an opened circular aluminum plate (10). A polytetrafluoroethylene film (11) is bonded and coated on the upper surface of the circular aluminum plate (10) through a heat-resistant adhesive, and the lower surface is covered with a polyester resin coating film (12) which is a heat sealing material. Thus, the peripheral edge of the circular aluminum plate (10) is heat-sealed to the lid (2) so as to be peelable. The thickness of the circular aluminum plate (10) is 40 μm, the thickness of the polytetrafluoroethylene film (11) is 12 μm, and the thickness of the polyester resin coating film (12) is 5 μm. The lower surface of the circular aluminum plate (10) is covered with a coating film (12) that the use of thick film as in the prior art to this, to lead to storage stability deterioration of the contents due to oxygen permeability of the seal portion Because. The synthetic resin that forms the coating film only needs to be a heat sealing material, and examples thereof include polyester-based, epoxy-based, and acrylic-based synthetic resins, and the thickness thereof is 1 to 15 μm, preferably 2 to 2. 10 μm. When the thickness is less than 1 μm, the sealing property is not ensured, and when it exceeds 15 μm, not only does oxygen permeate from the seal portion of the coating film, but also the cost increases.

Examples and comparative examples

  Tables 1 to 4 below show Examples 1 to 4 of the present invention in which a sealing compound is not required for the tightening portion, Comparative Example 1 in which the sealing compound is applied to the tightening portion, and Comparative Example 2 in which the sealing compound is not applied to the tightening portion. Show.

  Note: In the above, the epoxy resin is coated to give corrosion resistance.

  The following three tightening evaluation tests were carried out for the above examples and comparative examples. The results are shown in Table 2.

(1) Presence or absence of leakage due to permeation liquid Dye penetrant flaw detection agent (permeation liquid) is injected from the inner surface of the container to the tightened part of the container body and lid, and left for 5 days to determine whether or not the permeation liquid penetrates the outer surface. It was confirmed visually.

(2) Punk pressure (unit: Kpa)
After winding the container body and lid, the nozzle was inserted from the bottom of the container, air was injected, and the air pressure when punctured from the tightened part was measured.

(3) Pressure resistance test (Unit: 200N x 1 minute)
After tightening the container body and the lid, a load of 200 N was applied for 1 minute from above the container, and the presence or absence of leakage from the tightened part was visually confirmed.

  As shown in Table 2, the aluminum containers that do not require a sealing compound in the tightening portions of Examples 1 to 4 should all have good sealing properties, similar to the Al container of Comparative Example 1 that has been sealed. Was confirmed.

It is a vertical sectional view of the important section showing the embodiment of the present invention.

Explanation of symbols

(1) Bottomed container body (2) Lid (3) (4) Polypropylene film (synthetic resin film)
(5) Winding part

Claims (4)

  In a sealed metal container formed by covering and tightening at least the top of the top and bottom of the container body, a synthetic resin film having a thickness of 10 to 500 μm is bonded and coated on at least one of the inner and outer surfaces of the container body A hermetically sealed metal container that does not require a sealing compound at the tightening portion.   2. The sealed metal container according to claim 1, wherein the inner synthetic resin film is made of polypropylene or polyethylene, and the outer synthetic resin film is made of polypropylene.   In a sealed metal container formed by covering and tightening at least the top of the top and bottom of the container body, a synthetic resin film having a thickness of 10 to 500 μm is bonded and coated on the inner surface of the cover. A sealed metal container that does not require a sealing compound at the fastening part.   4. A sealed metal container in which a sealing compound is not required for a tightening portion according to claim 3, wherein the synthetic resin film is made of polypropylene or polyethylene.

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