JPS607172Y2 - Easy-open packaging - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to an easy-to-open package.

Conventionally, easy-open packages have various problems with the bonding surfaces of the packaging materials.

Normally, heat sealing (including impulse heat sealing, etc.) is widely used as a bonding method, but research is currently underway to improve conventional heat sealing, particularly from the viewpoint of increasing seal strength and improving sealing performance. Various types of fruit have been obtained.

On the other hand, there is a demand for heat seals that can easily open the sealed part of the package to completely protect the package contents during storage or transportation and to take out the contents. However, there is still almost nothing that can be put into practical use,
In particular, the current situation is that there are almost no products that can be heat sterilized after packaging.

As a result of various studies to solve the above-mentioned problems, the inventor of the present invention discovered that when joining two packaging material surfaces, a layer of ethylene vinyl acetate copolymer is provided on one joint surface, and the other packaging material is By providing a layer of Mg-type ionomer on the bonding surface and heat-sealing the two layers, the easy-to-open package has a heat-sealed part that can be sterilized by heating after packaging. The present invention was completed based on this knowledge.

That is, the gist of the present invention is that when joining two packaging materials, a layer of ethylene vinyl acetate copolymer is provided on one joining surface, a layer of Mg type ionomer is provided on the joining surface of the other packaging material, and This is an easy-to-open package characterized in that a heat-sealed portion is formed through two layers.

In addition, as for the easy-open heat seal strength in this invention, the peel strength is 1300 to 1800 g/15 m,/m.
Refers to the width range.

Hereinafter, the present invention will be described in detail with reference to the drawings.

When joining two packaging material surfaces, as shown in FIG. 1, ethylene vinyl acetate copolymer 2a is provided on the joining surface of one packaging material 1a (hereinafter referred to as the first laminate material), and the other packaging material 1b is
An Mg type ionomer 2b is provided on the bonding surface of (hereinafter referred to as second laminate material).

Next, as shown in FIG. 2, the packaging materials 1a and 1b are moved outward in a predetermined direction so that the ethylene vinyl acetate copolymer 2a of the first laminate material and the Mg type ionomer 2b of the second laminate material are in contact with each other. Heat-sealing is performed by applying pressure and temperature for a predetermined period of time to form the heat-sealed portion 3.

Heat pressure for heat sealing may be applied from either side of the packaging material, or from both sides of the packaging material, as shown in FIG.

When the heat-sealed portion is unsealed, the heat-sealed portion 3 is easily opened without any damage due to peeling, as shown in FIG.

In the above, the ethylene-vinyl acetate copolymer constituting the first laminate has a density of 0.92 to 0.95 g/a and a vinyl acetate content of 25% by weight or less.

The Mg type ionomer of the second laminate is a metal-containing ionic copolymer obtained by ionizing an ethylene-methacrylic acid copolymer with Mg.

There is also a Na type ionomer, but the heat seal peel strength of Na type ionomer and ethylene vinyl acetate copolymer is less than 4009/15 ml, which means that there is almost no adhesion and practical sealing strength cannot be obtained.

The reason why the adhesive strength of Na is weaker than that of pigeon is thought to be because the Na type has a larger ionic cohesive force and thus has fewer free carboxylic acid groups that can contribute to adhesion.

Therefore, the Na and Mg types have completely different physical properties.

Next, in the above, the packaging materials 1a and lb constituting the first laminate material and the second laminate material include, for example, polyvinyl chloride, polystyrene, polyethylene, polypropylene, polycarbonate, polyamide, polyester, aluminum foil, paper, etc. These may be single or more layered structures.

Therefore, in the present invention, when the packaging material is polyvinyl chloride, polystyrene, polypropylene, polycarbonate, polyamide, polyester, etc., it is effective as a molding base material, and various container bodies can be constructed.

Moreover, when polyester, polyamide, polypropylene, aluminum foil, etc. are used as the packaging material, it is effective as a lid.

In the present invention, the layer of ethylene vinyl acetate copolymer or the layer of Mg type ionomer is provided on the packaging materials 1a and 1b by a conventional method, such as a dry lamination method, a coextrusion lamination method, etc. be able to.

Next, the conditions for heat sealing in the above are temperature 14
Pressure 5-40pSi/1nCh2 at 0-200℃ (7)
The range is preferred and can be selected as appropriate depending on the required sealing strength.

In the above-mentioned present invention, the sealed part (heat seal part) does not open during storage or transportation of the packaged contents, completely protects the contents, and allows heat sterilization after packaging. When it is desired to take out the package, the sealed portion of the package can be easily opened without damaging the packaging material.

The present invention can be used as a sealing method for various packages that require easy opening, including deep-drawn packages.

Next, the present invention will be explained in more detail with reference to Examples.

Example 1 As an ethylene vinyl acetate copolymer, a film DVS-5 (manufactured by Dia Plastic ■, vinyl acetate content 5%) with a thickness of 30 μm was prepared.

On the other hand, the following ionomer resins (a) and (b) were formed into films by the isofresion method to obtain films each having a thickness of 30 μm.

(a) 1 Corporen■D200. (Asahi Dow, Mg type ionomer, density 0.949/Cr!” Melting point 9
6°C9MI=3.5) (b) 1 Hyramin■1707yo (same as above, Na type, density 0.95・MI=Q, 9. Melting point 87'C) Next,
A 12 μ thick polyethylene terephthalate film (Toyobo, Nisbet [F]) was used as the base material, and Takelac A-385 (Takeda Pharmaceutical Co., Ltd.) was used as the adhesive.
The ethylene vinyl acetate copolymer film, Mg type ionomer film, and Na type ionomer film obtained above were laminated onto the base material using the hardening agent Takenate A-50 (same as above), A laminated material was obtained.

Using the laminated material obtained above, the bonding conditions are as follows:
Temperature 120°C, 140°C, 160°C9180°C
, 200°C1 pressure 3Qpsi/1nch", 15s
A film consisting of polyethylene terephthalate layer / ethylene vinyl acetate copolymer layer / Mg type ionomer single layer / polyethylene terephthalate layer, and polyethylene terephthalate layer / ethylene vinyl acetate copolymer layer / Na type ionomer layer / A B film consisting of a polyethylene terephthalate layer was obtained.

Then, a peel test was conducted on the above A film and B film at a tensile rate of 300 TrL/min to measure the heat seal strength.

The results are shown in Figure 4.

The graph in the figure shows that the A film according to the present invention provides approximately constant easy-open properties over a wide heat-sealing temperature range.

Furthermore, regarding the A film created in Example 1 above,
A peel test was conducted at a tensile speed of 30,077 L/m/min to measure the seal strength of the product which had been subjected to a boiling treatment in which the powder was immersed in boiling water at 90°C for three times.

The above results are shown in FIG.

This shows that it is not substantially affected by boiling at 90°C.

[Brief explanation of the drawing]

1, 2, and 3 show the structure of the packaging material of the easy-to-open package of the present invention, and each of FIGS. 1, 2, and 3 is a cross-sectional view of the packaging material. , FIG. 4 and FIG. 5 show the physical properties of the easy-to-open package of the present invention, and both FIGS. 4 and 5 are graphs showing the results of a peel test. la, lb...packaging material, 2a...ethylene vinyl acetate copolymer, 2b...Mg type ionomer, 3...heat sealing part.

Claims (1)

[Scope of utility model registration request] When joining two packaging materials, ethylene-vinyl acetate copolymer is applied to the joining surface of one packaging material, and M is applied to the joining surface of the other packaging material.
An easy-to-open package characterized by having a layer of g-type ionomer and forming a heat-sealed part through the two layers.