JPH07119085B2 - Labeled plastic bottles - Google Patents

Description

TECHNICAL FIELD The present invention relates to a plastic bottle used as a storage container for cosmetics such as shampoo, conditioner and hair blow, toilet detergents such as kitchen detergents and bath detergents. In particular, it relates to a labeled plastic bottle in which a label is integrated at the same time when the plastic bottle is molded.

[Conventional technology]

Conventionally, when a label is put on a plastic container for storing cosmetics, toiletries, etc., a paper label is printed on the front side, a vinyl acetate adhesive is applied to the back side, and it is attached in a post process after forming the container. Was common. Further, as another method of the labeling step, a label with an adhesive is used, and the label is attached to the container while peeling off the release paper on the back surface of the label. As these problems, since glue such as vinyl acetate is used, when used in a place around water such as a bath or kitchen, there are drawbacks such as peeling and tearing of the label, and there are many problems in appearance. It has occurred.

Therefore, recently, we have applied a heat-sensitive adhesive to the back of the label,
A molding method has been proposed and carried out in which a label is held in advance in a mold for molding a container, the adhesive on the back surface of the label is melted by heat during molding of the container, and the label is integrated with a plastic bottle.

[Problems to be Solved by the Invention]

In this way, labels used for so-called in-mold molding, in which the labels are integrated simultaneously with the molding of the plastic bottles in the mold for molding the plastic bottles, have been required to have a great design in recent years. Those with a metallic luster as seen on the label are required.
However, if the outermost layer of the label is stamped with a metal foil in order to impart a metallic luster, the metal foil rubs against the mold when the label is held in the mold, which significantly impairs the design. The problem occurs.

As an improved label to avoid this problem, for example, as disclosed in JP-A-60-21244, a metal thin film layer is provided in the middle and a stretched plastic film is provided on the surface (outermost layer). Labels are known. By using a structure in which a stretched plastic film is provided on the surface of the label (outermost layer) in this way, although the problem that the metal foil rubs against the mold can be avoided, using a label with such a structure, Wrinkles occur on the label because the stretched plastic film shrinks due to the heat in the mold,
A new problem has arisen that the metal thin film layer is cracked and the appearance is impaired.

Therefore, it is an object of the present invention to provide a labeled plastic bottle, which has a structure in which the label is provided with metallic luster, but which can integrate the label at the same time as molding of the plastic bottle without impairing the design.

[Means for Solving the Problems]

The present invention, in order to solve the above problems, a label previously held in a mold for molding a plastic bottle, a labeled plastic bottle that is integrated by heat during molding of the plastic bottle, wherein the label is a label. There is provided a labeled plastic bottle characterized in that a metal thin film layer obtained by pressing a metal foil is provided on a base material layer, and an unstretched plastic film is further provided on the metal thin film layer.

[Action]

According to the present invention, by using the label provided with the unstretched plastic film as the protective layer on the metal thin film layer, the metal thin film layer does not come into direct contact with the molding die of the plastic bottle. It does not rub against the mold and does not impair the design of the metal thin film layer. And by using an unstretched plastic film as the protective layer, the label does not shrink due to heat in the mold,
Moreover, after the plastic bottle is molded, the plastic bottle shrinks following the shrinkage of the plastic bottle, so that wrinkles do not occur on the label and cracks can be prevented from occurring in the metal thin film layer.

〔Example〕

The specific structure of the in-mold label of the present invention is as follows. That is, protective layer (plastic film) /
It is composed of a metal thin film layer (metal foil) / printing layer / base material layer (synthetic paper) / adhesive resin layer.

Each constituent layer will be described. First, the base material layer has printability,
Synthetic paper based on polypropylene is suitable from the viewpoint of metal foil pressing suitability and moldability.

Next, a process of forming a metal thin film layer by pressing a metal foil will be described. The metal used as the base of the metal foil is usually gold or silver, and its structure is composed of release paper / metal foil / heat-sensitive adhesive layer. The heat-sensitive adhesive is usually an acrylic resin or vinyl chloride acetate resin. A metal thin film layer is formed on the base material layer by pressurizing the metal foil having the above-mentioned configuration from the release paper side with a metal mold for hot-pressing the foil and pressing the metal foil into a required shape. In addition, when providing the printing layer on the base material layer (synthetic paper), it is possible to appropriately select from printing methods such as general gravure printing, offset printing, letterpress printing by resin letterpress, and the like. It is not something that will be done.

Metal foil stamping is done on this printed layer or substrate layer (synthetic paper)
It is carried out directly on the printed layer or on the base material layer (synthetic paper) and can be sufficiently adhered with an acrylic resin or vinyl chloride acetate-based heat-sensitive adhesive.

The adhesive resin layer on the surface of the base material layer (synthetic paper) is necessary for thermal adhesion to a plastic bottle, and is usually composed of the same resin-based adhesive as that of the plastic bottle.

Finally, the protective layer (plastic film) laminated on the metal thin film layer (metal foil pressing) will be described. An unstretched polypropylene film is most suitable for this film, but a polyethylene-based film can be used as long as it is an unstretched film. On the other hand, in the case of an unstretched film, due to its strong shrinkage force that shrinks due to heat, it shrinks due to heat when it is held in the mold (before being integrated into a plastic bottle), and After being integrated into the bottle, it is not suitable because it cannot follow the shrinkage that occurs after molding of the plastic bottle and wrinkles occur on the label.

Therefore, in the present invention, the shrinkage does not occur in the mold (the stage before being integrated with the plastic bottle) but shrinks following the shrinkage of the plastic bottle after molding (in the state of being integrated with the plastic bottle). It is important to use an unstretched film capable of

Further, in the present example, for the lamination of the protective layer (unstretched plastic film) and the base material layer (synthetic paper) on which the metal thin film layer is formed, a usual dry laminating method using a urethane adhesive or the like is used. However, it is also possible to use a sand laminating method in which an unstretched plastic film is laminated while the resin is extruded by an extruder. The laminated film described above is punched into a label shape and used as an in-mold label.

In the present invention, as a means for integrating the in-mold label and the plastic bottle in the mold,
Blow molding, injection molding, etc. can be mentioned.When using any molding method, the protective layer side of the label is placed facing the mold in the molding die, and the plastic bottle is placed on the adhesive resin layer side. By pouring the resin to be formed, both can be welded and integrated.

[Example 1] As a base material layer of an in-mold label, polypropylene-based synthetic paper, trade name YUPO (manufactured by Oji Yuka Synthetic Paper Co., Ltd .:
A thickness of 100 μm) was used. Printing on the base material layer was carried out by a gravure printing method using a urethane-based ink, Lamister 2 liquid (trade name, manufactured by Toyo Ink Co., Ltd.). The metal thin film layer is formed by pressing a metal foil by using a metal foil composed of a gold foil using a vinyl chloride-based adhesive as a heat-sensitive adhesive, and pressing the foil on the printing layer with a mold heated to a temperature of 100 ° C. went. The adhesive resin layer for adhering to the plastic bottle is a urethane adhesive.
EPS75A / KW40 (manufactured by Dainippon Ink and Chemicals, Inc.) was used to apply to the back surface of the base material layer (the side opposite to the printing layer) to form an adhesive resin layer. An unstretched polyethylene film, trade name M-14P (Tama Poly Co., Ltd .: thickness 40 μm), was laminated on the printed layer as a protective layer by a dry laminating method.

The laminated film produced by the above method was punched into a label shape and prepared as a label for an in-mold label.

On the other hand, as the resin for the plastic bottle, a high-density polyethylene resin, trade name B5032A (manufactured by Tozen Petrochemical Co., Ltd., antistatic agent kneaded type) was used. Protective layer (unstretched polyethylene film) with the above label in the mold for hollow molding of this plastic bottle.
Place the side facing the mold, then insert the molten resin into the mold and blow the compressed air to form a plastic bottle, and at the same time melt the adhesive resin layer by the heat, label and plastic bottle Welded and integrated. As a result, the metal thin film layer of the label was not rubbed in the mold, and the wrinkles did not occur on the label, and the metal thin film layer was not cracked, so a highly-designed labeled plastic bottle was obtained. Was given.

[Example 2] Instead of the label used in Example 1 above, an unstretched polypropylene film as an unstretched plastic film on a metal thin film layer (metal foil pressing), trade name FHK (manufactured by Nimura Chemical Co., Ltd .: thickness 40 μm) was used to create a plastic bottle with an integrated label. The conditions of the printing layer, the resin of the adhesive resin layer, the laminating method, the resin forming the plastic bottle, and the like were all the same as in Example 1. As a result, similarly to Example 1, the metal thin film layer was not rubbed, cracks were not generated, and a labeled plastic bottle having a very high design property was obtained.

[Comparative Example 1] Instead of the label used in the above example, a plastic bottle in which a conventional thin label is integrated with a label, which is a structure in which an unstretched plastic film is not laminated on a metal thin film layer (metal foil pressing). It was created. In addition,
The conditions of the printing layer, the resin of the adhesive resin layer, the laminating method, the resin forming the plastic bottle, and the like were all the same as in Example 1. As a result, since the metal thin film layer is the outermost layer of the label, it rubs in the mold,
The metal thin film layer impaired the design, resulting in a plastic bottle with a very low commercial value.

[Comparative Example 2] Instead of the label used in the above examples, a polypropylene film with a stretched polypropylene film (trade name: PYRENE 1931 (manufactured by Toyobo Co., Ltd .: thickness 30 μm) on a metal thin film layer (metal foil pressing).
A plastic bottle in which a label laminated with m) was integrated was prepared. The conditions of the printing layer, the resin of the adhesive resin layer, the laminating method, the resin forming the plastic bottle, and the like were all the same as in Example 1. As a result, since the metal thin film layer was not the outermost layer of the label, it did not cause rubbing in the mold, but contracted due to the heat in the mold because the stretched film was used as the protective layer, After being integrated into a plastic bottle,
The plastic bottle after molding could not follow the shrinkage, and the label wrinkled and the metal thin film layer cracked. Therefore, the designability of the metal thin film layer is impaired, and the plastic bottle has a low commercial value.

〔The invention's effect〕

According to the labeled plastic bottle of the present example, by providing a metal thin film layer by pressing a metal foil on the label base material layer as a label, and by using an unstretched plastic film provided on the metal thin film layer. ,
In the mold for molding the plastic bottle, the metal thin film layer formed by pressing the metal foil on the label is protected by the unstretched plastic film when the plastic bottle and the label are integrated by the heat during the molding of the plastic bottle. , The metal thin film layer is not rubbed in the mold, the gloss of the metal thin film layer can be prevented from being impaired, and the unstretched plastic film does not shrink due to the heat in the mold, and the plastic bottle is molded. Since the shrinkage of the label can be followed, it is possible to prevent the label from wrinkling due to the shrinkage of the plastic bottle after molding. Therefore, it is possible to obtain a labeled plastic bottle having a very excellent appearance and without causing cracks in the metal thin film layer.

Claims (1)

[Claims] 1. A labeled plastic bottle in which a label previously held in a mold for molding a plastic bottle is integrated by heat during molding of the plastic bottle, wherein the label is a metal on a label base layer. A labeled plastic bottle, comprising a metal thin film layer formed by foil stamping, and an unstretched plastic film provided on the metal thin film layer.