JPS5823633Y2 - packaging material - Google Patents

Description

[Detailed description of the invention] The present invention relates to an improved packaging material that prevents the quality of the contents from deteriorating due to adsorption of moisture in the packaging bag or changes over time due to moisture contained in the contents. , is effective for long-term storage, prevents the occurrence of rust on the outer layer metal foil, and has good thermoliquid properties.

Conventionally, chemicals that avoid quality changes and quality deterioration due to moisture,
Food products are packaged in packaging bags made of packaging materials with metal foil such as aluminum foil attached as a moisture-proof layer. Although this is effective in preventing moisture from entering from the outside, the moisture content inside the packaging bag There was a drawback that it was unsuitable for packaging items whose contents change over time due to the moisture contained in the product, but as a result of various experimental studies, the inventor of the present invention has developed a present invention that does not have this drawback. I got it.

Below, a specific example of the present invention will be explained with reference to the drawings.
The inner surface of a metal foil 1 such as aluminum foil with a thickness of about 20 μm is coated with a rust-preventing material such as lacquer such as acrylic, polyester, vinyl, or cellulose, or synthetic resin such as polyethylene or polypropylene to a thickness of 0. 2-2
A rust preventive coating layer 2 of about 0 μm is layered, and calcium chloride, silica gel, zeolite, etc. with a particle size of 0.1 to 20 μm is layered on the layer 2.
Moisture-absorbing substances of about μ are mixed with polyvinyl alcohol, epoxy,
A moisture-absorbing paint prepared by mixing 5 to 50% by weight of a binder solution containing polyurethane, polyacrylic acid, casein, etc. as a binder is applied at a coating amount of about 1 to 10 g/m2 to form a moisture-absorbing layer 3, and further on the moisture-absorbing layer 3. Synthetic resins with thermal adhesive properties such as polyolefin resins such as polyethylene and polypropylene are melt-extruded, dry laminated,
A thermal adhesive layer 4 having a thickness of 25 μm or less, preferably 10 to 25 μm, is laminated by an appropriate means, and the outer surface of the metal foil 1 is coated with materials to improve various properties such as rigidity, smoothness, and printability. For this purpose, an exterior film material 5 with a thickness of about 10 to 100 μm, such as a synthetic resin film such as polyester film, polypropylene film, or nylon film, or paper material such as glassine paper, kraft paper, or roll paper, is coated with an isocyanate-based, epoxy-based, etc. solution. Lamination is performed using a suitable adhesive 6 such as a mold adhesive or a molten synthetic resin.

In the figure, 7 is a printed layer applied to the inner or outer surface of the exterior membrane material 5.

In general, polyolefin resins such as polyethylene and polypropylene are said to be moisture-proof, but even so, for those with a thickness of about 15 to 20 μm, it is 1 to 5 mg/cm224
It has weak moisture permeability of about 300 hrs.

Since the present invention is a packaging material as described above, it can be put to practical use as a packaging bag by using known bag making methods such as the three-sided sealing method and the back sealing method, with the thermal adhesive layer 4 as the inner surface.

In the present invention, a moisture absorbing layer 3 is layered on the inner surface of the metal foil 1 via a rust-preventing coating layer 2, so that the metal foil 1 blocks moisture from entering from the outside and prevents moisture from entering inside the packaging bag or the contents. Thermal adhesive layer 4 has weak moisture permeability to remove moisture in objects.
The contents of the packaging bag are absorbed by the moisture absorbing layer 3 on the inner surface of the metal foil 1, so that the contents inside the packaging bag contain moisture from the outside, moisture from the inside, and moisture from the inside.
It is possible to effectively prevent quality deterioration due to moisture, and even if the moisture absorption layer 3 absorbs moisture and becomes wet, a rust-preventing coating layer 2 is formed between the metal foil 1 and the metal foil 1. Therefore, water and humidity do not come into direct contact with the metal foil 1, preventing the occurrence of rust on the inner surface of the metal foil 1, which is preferable from a sanitary standpoint, and also preventing the occurrence of pinholes in the metal foil 1 due to rust. The metal foil 1 can effectively maintain its water and moisture blocking effect over a long period of time.

In addition, since the present invention has a thermal adhesive layer 4 as a bottom layer on the inner surface of the moisture absorbing layer 3, the moisture absorbing substance mixed in the moisture absorbing layer 3 does not come into direct contact with the contents, making it sanitary. The adhesive layer 4 makes it possible to easily obtain an airtight packaging bag.

Incidentally, if it is necessary to provide further moisture absorption performance, fine through holes 8 are formed in the thermal adhesive layer 4.

[Brief explanation of the drawing]

The figure is a partially enlarged sectional view. 1...Metal foil, 2...Rust prevention coating layer, 3
...Moisture absorbing layer, 4...Thermoadhesive layer.

Claims (1)

[Scope of utility model registration request] A rust-proofing coating layer 2 is layered on the inner surface of the metal foil 1, and a moisture-absorbing layer 3 is layered on the rust-proofing coating layer 2.
Thermal adhesive layer 4 with a thickness of 20μ or less and having weak moisture permeability on the surface of
A packaging material made by coating and layering.