JP4574757B2 - Blister pack - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a blister pack for packaging various articles such as electric appliances such as dry batteries, daily necessities, toys, stationery, cosmetics, medicines, medical instruments, and accessories.
[0002]
[Prior art]
Blister packs are often used to wrap, display and sell products such as dry batteries and toothbrushes. This blister pack is usually composed of a plastic sheet molded body in which a recess for accommodating an article is formed, and a sheet base material (mounting paper) formed of cardboard or the like that covers the recess after the article is accommodated. Yes.
[0003]
As a method of attaching the plastic sheet molded body to a sheet base material, (a) a method in which both peripheral portions are stapled, (b) two opposite ends of the plastic molded body are folded into a “U” shape, A method of sliding and attaching the sheet base material to the groove, (c) a method of bonding the plastic sheet molded body and the sheet base material by thermocompression bonding via a hot melt adhesive at the periphery of the concave portion for accommodating the article, etc. There is. Recently, a method (c) for thermocompression bonding using a hot-melt adhesive is widely employed because mass production by an automatic blister packaging machine is easy and the appearance is excellent.
[0004]
However, with the conventional method of bonding using a hot melt adhesive, in particular, after bonding a plastic sheet molded body having a large number of recesses and a large sheet substrate, it is divided into individual blister packs by punching or the like. In this case, there is a problem that the plastic sheet molded body and the sheet base material are not uniformly bonded due to variations in pressure and temperature during bonding, uneven thickness of each sheet, and the like. In addition, since the sheet base material is usually formed of paper, it is not only vulnerable to water wetting, but also when the product is taken out from the blister pack and discarded as garbage, the plastic sheet molded body and the paper sheet base are used. It is necessary to sort the materials.
[0005]
On the other hand, from the viewpoint of environmental protection, the plastic sheet molded body is changing from being made of vinyl chloride resin to being made of polyester, and is excellent in adhesiveness to this polyester and can be discarded at the same time as the polyester sheet molded body. There is a need for blister packs comprising a polyester sheet substrate. However, for example, when a polyester sheet molded body and a polyester sheet base material are bonded using a conventional hot melt adhesive, bubbles are generated in the bonded portion, and the sheet base material is peeled off during the distribution process of the product. Has a point. In addition, the adhesive strength is low, and it is particularly easy to peel off when a heavy article such as a dry battery is packaged or when the temperature is high and the adhesive is softened.
[0006]
[Problems to be solved by the invention]
Accordingly, an object of the present invention is to provide a blister pack capable of bonding a plastic sheet molded body and a sheet base material uniformly and firmly and in which both are difficult to peel off during the distribution process.
Another object of the present invention is to provide a blister pack which is resistant to water, does not peel even when a heavy article is packaged, and can be discarded as garbage without separating the plastic sheet molded body and the sheet base material. is there.
Still another object of the present invention is to provide a blister pack in which a plastic sheet molded article and a sheet base material are not easily separated in the distribution process, do not require time and effort for disposal, and do not adversely affect the environment.
[0007]
[Means for Solving the Problems]
As a result of intensive studies to achieve the above object, the inventors of the present invention can adhere the plastic sheet molded body and the sheet base material uniformly and firmly to each other by making the sheet base material a specific layer configuration, The present invention has been completed by finding that it becomes easy to dispose of the product after it is taken out.
[0008]
That is, the present invention is a blister pack having a plastic sheet molded body having a recess for accommodating an article and a sheet base material for closing the recess, wherein the sheet base material is a plastic film and the plastic. It is composed of a low-density polyethylene layer and a heat-adhesive resin layer containing 80% by weight or more of an ethylene-α-olefin random copolymer rubber or an acid-modified product sequentially provided on one side of the film , and plastic sheet molding Provided is a blister pack in which a plastic film constituting a body and a sheet substrate is formed of polyester .
[0009]
In this blister pack, the heat-adhesive resin layer may further contain an ethylene-vinyl acetate copolymer.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings as necessary. FIG. 1 is a perspective view showing an example of the blister pack of the present invention, and FIG. 2 is a cross-sectional view of the blister pack of FIG.
[0011]
The blister pack 1 includes a rectangular plastic sheet molded body 2 formed with a substantially rectangular parallelepiped recess 2a for accommodating an article 4, and a sheet base that is bonded to the plastic sheet molded body 2 and closes the recess 2a. A hook hole 5 is provided at the center of one end. The sheet base 3 is composed of a plastic film 6 and a thermoadhesive resin layer 8 containing an olefin rubber provided on one surface of the plastic film 6 via a low density polyethylene layer 7.
[0012]
The plastic sheet molded body 2 is formed by subjecting a sheet formed of a known or known plastic material used as a packaging material such as polyester, polyvinyl chloride, or styrene resin to a molding process such as vacuum molding or pressure molding. Can be obtained. The plastic sheet molded body 2 is preferably formed of polyester such as polyethylene terephthalate from the viewpoints of environmental protection, transparency, strength, and the like. The thickness of the plastic sheet molded body 2 can be appropriately selected in consideration of moldability, strength, cost, etc., but is generally about 0.15 to 1 mm.
[0013]
The plastic film 6 constituting the sheet substrate is not particularly limited as long as it is a plastic film having a self-supporting property. For example, a polyester film (for example, a film such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate), Examples include polyolefin films (for example, films of polypropylene resins such as polypropylene and propylene-ethylene copolymers), synthetic paper (for example, polyester synthetic paper, polyolefin synthetic paper, and the like). The plastic film may be a stretched film or an unstretched film. Among these, a polyester film such as a biaxially stretched polyethylene terephthalate film and a synthetic paper such as a void-containing polyester synthetic paper (for example, trade name: Crisper) are preferable. The thickness of the plastic film 6 can be selected within a range that does not impair the strength, workability, and the like, and is, for example, about 20 to 100 μm, preferably about 30 to 90 μm.
[0014]
Examples of the low density polyethylene constituting the low density polyethylene layer 7 include polyethylene having a density of about 0.90 to 0.93 g / cm ³ and linear low density polyethylene. The thickness of the low density polyethylene layer 7 is, for example, about 20 to 80 μm, preferably about 30 to 70 μm. The low density polyethylene includes those having a small amount of propylene, vinyl acetate, acrylic acid or the like as a copolymerization component.
[0015]
The heat-adhesive resin layer 8 contains olefin rubber. Examples of the olefin rubber include ethylene-α-olefin random copolymer rubbers such as ethylene-propylene random copolymer and ethylene-1-butene random copolymer. Examples of such ethylene-α-olefin random copolymer rubber include trade name “Tuffmer” (manufactured by Mitsui Chemicals, Inc.). In the ethylene-α-olefin random copolymer rubber, the ethylene content is preferably about 60 to 95 mol%. The content of the olefin rubber in the heat-adhesive resin layer 8 is preferably 50% by weight or more, and more preferably 80% by weight or more. As the olefin rubber, acid-modified products of these ethylene-α-olefin random copolymer rubbers can also be used. As such an acid-modified product, an unsaturated carboxylic acid-modified ethylene-α obtained by grafting an unsaturated dicarboxylic acid such as maleic acid or an acid anhydride thereof onto an unmodified ethylene-α-olefin random copolymer. -Olefin random copolymers. Specific examples include trade name “Admer” (Mitsui Chemicals) and “Modic” (Mitsubishi Chemical).
[0016]
The heat-adhesive resin layer 8 may contain a resin component other than the olefin rubber, and as such a component, a resin exhibiting heat adhesion, for example, an ethylene-based resin such as an ethylene-vinyl acetate copolymer. Etc. The heat-adhesive resin layer 8 may contain tackifiers such as petroleum resins and terpene resins; various additives such as antioxidants and lubricants.
[0017]
The thickness of the heat-adhesive resin layer 8 can be appropriately selected within a range that does not impair the adhesive strength and the like, but is generally 20 μm or more (for example, about 20 to 50 μm). The total thickness of the low density polyethylene layer 7 and the thermal adhesive resin layer 8 is preferably 50 μm or more (for example, about 50 to 130 μm).
[0018]
The sheet base material 3 is formed by, for example, melt extrusion coating a resin composition containing low-density polyethylene and a resin composition containing a heat-adhesive resin on the surface of a plastic film 6 in one or two stages. It can be manufactured by forming the density polyethylene layer 7 and the heat-adhesive resin layer 8.
[0019]
In this example, since the heat-adhesive resin layer 8 contains an olefin-based rubber, when the plastic sheet molded body 2 and the sheet base material 3 are bonded by thermocompression bonding, there are variations in pressure and temperature depending on the location, Even if the plastic sheet molded body 2 and the sheet base material 3 have some thickness unevenness, the plastic sheet molded body 2 and the sheet base material 3 are bonded uniformly and firmly. Moreover, even if the heat-adhesive resin layer 8 is softened at a high temperature of 35 to 50 ° C., since the adhesiveness (hot tack property) is good, the sheet substrate 3 is peeled off from the plastic sheet molded body 2 in the product distribution process. There is nothing. In addition, since both the plastic sheet molded body 2 and the sheet base material 3 are formed of plastic, there is no need for sorting when discarded as garbage.
[0020]
Further, since the low-density polyethylene layer 7 having excellent thermal conductivity and a wide melting temperature range is interposed between the plastic film 6 and the heat-adhesive resin layer 8, the low-density polyethylene is heated by heat at the time of thermocompression bonding. The layer 7 is melted quickly and uniformly, and the heat is uniformly transferred to the heat-bonding resin layer 8 and the low-density polyethylene serves as a cushion, or the plastic sheet molded body 2 and the sheet base material 3 Adheres more uniformly and firmly.
[0021]
The low-density polyethylene layer 7 is not necessarily provided, and the required effect can be obtained only by the heat-adhesive resin layer 8 containing olefin rubber. Moreover, when providing the low density polyethylene layer 7, the said thermoadhesive resin layer 8 does not necessarily need to contain the olefin type rubber. In this case, even if the thermal adhesive resin layer 8 is formed of another adhesive resin, good uniform adhesiveness can be obtained. Examples of such adhesive resins include those mainly composed of an ethylene-vinyl acetate copolymer, an ethylene-acrylic acid copolymer, and a tackifier such as a petroleum resin or a terpene resin.
[0022]
In a preferred embodiment of the present invention, the plastic sheet molded body and the sheet base material are formed of polyester, and a low-density polyethylene layer and a heat-adhesive resin layer containing an olefin rubber are provided in this order on one side of the plastic film. It has been. Such a blister pack has an advantage that, in addition to the above-described effects, the environment is not adversely affected during disposal.
[0023]
The blister pack of the present invention can be produced, for example, as follows. That is, after accommodating a desired article (for example, a dry cell) in a continuous portion of a plastic molded body in which a large number of recesses for accommodating articles are formed by vacuum forming or pressure forming, a large sheet base material is stacked. In addition, individual blister packs can be obtained by punching the bonded portion after the continuous portion of the plastic molded body and the large sheet base material are bonded by thermocompression bonding of the peripheral portion of the concave portion. Note that a plastic molded body having one recess and a sheet base having a corresponding size are used, and after the article is accommodated in the recess, the plastic molded body and the sheet base are thermally bonded at the peripheral portion of the recess. By doing so, it is also possible to manufacture individual blister packs.
[0024]
In the blister pack of the present invention, since the plastic sheet molded body and the sheet base material are fixed with high adhesive strength, even a heavy article can be reliably accommodated and held for a necessary period. Therefore, it can be suitably used for packaging a wide range of articles such as electric appliances such as dry batteries, daily necessities, toys, stationery, cosmetics, medicines, medical instruments, and accessories.
[0025]
【The invention's effect】
According to the blister pack of the present invention, since the sheet base material has a specific layer structure, the plastic sheet molded body and the sheet base material can be bonded uniformly and firmly, so that the plastic sheet molding is performed in the distribution process. The body and the sheet substrate are difficult to peel off.
Further, since the sheet base material is made of a plastic film, it is resistant to water, does not peel off even when a heavy article is packaged, and can be discarded as garbage without sorting the plastic sheet molded body and the sheet base material.
Furthermore, when the plastic sheet molded body and the sheet base material are formed of polyester, no toxic gas is generated even when discarded and incinerated, and the influence on the environment is small.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an example of a blister pack of the present invention.
2 is a cross-sectional view of the blister pack of FIG.
[Explanation of symbols]
1 Blister pack 2 Plastic sheet molding
2a Recess 3 Sheet base 6 Plastic film 7 Low density polyethylene layer 8 Thermal adhesive resin layer

Claims (2)

A blister pack comprising a plastic sheet molded body having a recess for accommodating an article and a sheet base material for closing the recess, wherein the sheet base material is sequentially provided on one side of the plastic film and the plastic film. A low-density polyethylene layer and a heat-adhesive resin layer containing 80% by weight or more of an ethylene-α-olefin random copolymer rubber or an acid-modified product thereof; A blister pack in which the plastic film is made of polyester . The blister pack according to claim 1, wherein the heat-adhesive resin layer further contains an ethylene-vinyl acetate copolymer.

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