JPH022585Y2 - - Google Patents

Description

[Detailed explanation of the idea]

This invention relates to a packaging bag formed by thermal bonding, in which a desired packaging bag is formed by polymerizing appropriate portions of a packaging base material and thermally bonding the polymerized portions together. Conventional packaging bags of this type have been designed to have as close to perfect adhesion as possible at the heat-adhesive part, making it difficult for people who lack the strength of their fingers, such as the elderly and young children, to open and tear the bag. There was a problem that made it extremely difficult. In addition, there are packaging bags that have solved this problem, but contrary to the bags mentioned above, they have good tearability when opened, but have poor thermal adhesion and may absorb moisture or leak the contents of the package. There was a problem. That is, conventional packaging bags of this type have a trade-off between thermal adhesion and tearing. However, since these are essential requirements for this type of packaging bag, conventional packaging bags had to be improved. The purpose of this invention is to improve the above-mentioned problems and provide a thermally bonded packaging bag in which the thermal bonding and opening/tearing are in the best condition during use. The configuration is described below. This idea consists of two aluminum foils placed on a paper base material 1.
A packaging base material 5 comprising a thermoplastic synthetic resin layer 3 formed on the aluminum foil 2, and a heat-sealable adhesive layer 4 formed on the thermoplastic synthetic resin layer 3.
In the packaging bag formed by thermal adhesion, the packaging bag is formed by exposing the heat-sealing adhesive layer 4 to a suitable portion and exposing the thermoplastic synthetic resin layer 3 to heat.
is a packaging bag formed by thermal adhesion, in which a low-foaming layer 6 is formed, and desirably, the heat-sealing adhesive layer 4 is formed by applying a self-emulsifying ethylene acrylic acid resin aqueous solution 7 to two sides of aluminum foil and drying it, and more preferably, The above self-emulsifying ethylene acrylic acid resin aqueous solution 7 was mixed with 1 to 6% solid content of water-soluble acrylic resin 8 and 1 to 20% solid content of polyethylene lubricant 9. It is sufficient to provide it on two sides of the foil. To explain in more detail with reference to the drawings, FIG. 1 is an enlarged sectional view of the packaging material from which the packaging bag of the present invention is to be formed. As shown in the figure, the paper base material 1 is not moisture-proof in itself, so an aluminum foil 2 is pasted on it.The adhesive A for this pasting is an emulsion-based water-soluble adhesive that has good bag strength and tearability. adhesive or starch-based adhesive. In addition to the adhesives mentioned above, polyethylene, polypropylene, etc. can also be used, but in order to improve the strength of the bag, the adhesive layer must be thicker, and on the other hand, the same layer must be thinner in order to prevent the bag from being opened and torn. However, the process is complicated in that it is necessary to form layers with two types of layers: a thick portion and a thin portion. A low foaming thermoplastic synthetic resin layer 3 is provided on the aluminum foil 2 surface. The low-foaming thermoplastic synthetic resin layer 3 is made of materials mainly composed of EVA, EAA, PE, and PP, to which a foaming agent (Celmic MB3013 manufactured by Sankyo Kasei Co., Ltd.) is added. A low foaming film is formed by applying molten polyethylene to two sides of the aluminum foil, and the low foaming film is laminated to the molten surface, or organic titanium, for example, is applied to the two sides of the aluminum foil. , polyethyleneimine, polyurethane resin, or the like as the anchor coating agent B, it is also possible to directly laminate a low-foaming thermoplastic synthetic resin layer on the coated surface using an extrusion lamination method. In this way, the low-foaming thermoplastic synthetic resin layer is strongly integrated with the aluminum foil. The expansion ratio of the thermoplastic synthetic resin layer above is 1.1.
~6.0 times is preferable in terms of heat sealing and tearing/opening. In this way, for example, polyethylene with low foaming has high elasticity when compared to unfoamed polyethylene, and the packaging base material can be easily torn and opened with the force of a small fingertip, and the packaging bag can be opened and torn. Needless to say, this is easier than packaging bags having a foamed polyethylene layer. The upper surface of the low-foaming thermoplastic synthetic resin layer 3 is subjected to corona discharge treatment or the like to improve wettability, and then coated with a self-emulsifying ethylene acrylic acid resin aqueous solution 7. In other words, this heat-sealable adhesive layer 4 has a strong adhesive force, generates little static electricity, and can be thinned.
By setting the thickness to 1.5 μ to 8 μ, good tearability is achieved without impairing the tearing effect of the low-strength layer 6. Moreover, if the thickness is less than 1.5 μm, the opening and tearing will be worsened. In addition to forming the self-emulsifying ethylene acrylic acid resin aqueous solution 7 alone to form the heat-sealable adhesive layer 4 as described above, a water-soluble acrylic resin 8 (Rohm & Haas Japan Co., Ltd.) is added to this as shown in the table below. ) Primal WL-81) and polyethylene lubricant 9 (ethylene acrylic acid resin
By adding ALMIC-W-300 slip agent (manufactured by Co., Ltd.), it is possible to not only improve the thermal adhesion to form the packaging bag, but also improve the tearability and slipperiness of the bag at the same time. becomes. Furthermore, both the self-emulsifying ethylene acrylic acid resin aqueous solution 7 mixed with the water-soluble acrylic resin 8 and the self-emulsifying ethylene acrylic acid resin aqueous solution 7 mixed with the polyethylene lubricant 9 have thermal adhesive properties. In addition to being good, the former allows for bags with good tear-opening properties, and the latter allows for bags with good slipperiness.

【table】

[Table] The structure of the packaging base material 5 of the packaging bag of the present invention is as described above, and as shown in FIG. It is made into a cylinder shape, and a second heat-sensitive adhesive is applied at appropriate positions in the vertical direction to package the contents. In this case, as shown in FIG. 3, after the first heat-sensitive bonding, the adhesive part is laid down to one side before the second heat-sensitive bonding is performed.
At the time of heat-sensitive bonding, the bonded portion has four layers on the above-mentioned prone portion, and two layers on the other portions. There is a level difference near the boundary between the fourth layer and the second layer. This idea has a low foam layer 6 in the structure of the packaging base material 5.
Since it has elasticity, the gap between the steps can be filled even under low pressure.Therefore, during heat-sensitive bonding, there is no leakage of heat bonding near the boundary between the fourth layer and the second layer. It goes without saying that this will not occur,
With this configuration, there is no need to expose the device to heat for a long time at high temperatures as in the conventional case. Therefore, there is no color change on the surface of the packaging bag, no damage to the printed contents, and since thermal bonding can be performed at low pressure, there is no occurrence of damage such as pinholes caused by high pressure sealing. As described above, the present invention completely improves the conventional problems mentioned at the beginning, and also has the moisture-proof properties required for this type of packaging bag and packaging suitability such as insertion and removal of contents into the packaging bag. Therefore, it can be said to be the best packaging bag for manufacturers and end users.

[Brief explanation of drawings]

FIG. 1 is an enlarged sectional view of the packaging material used in the present invention, FIG. 2 is a perspective view showing the adhesive state of the present invention, and FIG. 3 is a perspective view of the present invention. 1...Paper base material, 2...Aluminum foil, 3...
...Thermoplastic synthetic resin layer, 4... Heat sealable adhesive layer,
5... Packaging base material, 6... Low foaming layer, 7... Self-emulsifying ethylene acrylic acid resin aqueous solution, 8... Water-soluble acrylic resin, 9... Polyethylene lubricant.

Claims (1)

[Claims for Utility Model Registration] 1. Aluminum foil is laminated on a paper base material, a thermoplastic synthetic resin layer is formed on the aluminum foil, and a heat sealable adhesive is formed on the thermoplastic synthetic resin layer. In the packaging bag formed by thermal bonding, the packaging bag is formed by exposing the heat-sealable adhesive layer of the packaging base material layered to heat at an appropriate portion of the packaging base material, in which the thermoplastic synthetic resin layer has a low temperature. A packaging bag formed by thermal bonding of foam. 2. A packaging bag formed by thermal bonding according to claim 1), wherein the heat-sealable adhesive layer is a dry coating layer made of a self-emulsifying ethylene acrylic acid resin aqueous solution. 3 The heat-sealing adhesive layer is made by mixing 1 to 6% of a water-soluble acrylic resin in the solid content ratio and 1 to 20% of the solid content of a polyethylene lubricant in the self-emulsifying ethylene acrylic acid resin aqueous solution. A packaging bag formed by thermal bonding according to claim 1).