JPH082584B2 - Labeled container - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention has a label for use as a storage container for cosmetics such as shampoo, conditioner and hair blow, toiletry products such as kitchen detergents and bath detergents. The present invention relates to a method for manufacturing a plastic bottle.

<Prior art> Conventionally, when sticking a label on a plastic container for storing cosmetics, toiletries, etc., a paper label is front-printed and a back surface is glued with vinyl acetate, etc. It was common to stick.

As another method in the labeling step, a label with an adhesive was used, and the label was attached to the bottle 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 it is used in a place with a lot of water such as a bath and kitchen, there are drawbacks such as peeling and tearing of the label, and there are many problems in appearance. It has occurred.

Therefore, recently, a heat-sensitive adhesive is applied to the back surface of the label, the label is pre-installed in the mold during bottle molding, and the adhesive on the back surface of the label is melted by the heat during container molding,
A molding method of integrating with a plastic bottle has been proposed. This molding method is commonly called in-mold molding.

<Problems to be Solved by the Invention> Conventionally, the label base material for in-mold molding (the thickest layer which is the outermost layer of the label on which printing is performed) used for plastic bottles has a problem of heat shrinkage during molding of the bottle. It is conceivable to use an unstretched film having excellent followability to heat shrinkage during bottle molding.

In this case, a polypropylene film is most suitable for the unstretched film because of problems such as printability and heat resistance.

However, the plastic bottle body is kneaded and molded with an antistatic agent in order to prevent dust from adhering to it.
Since an ordinary plastic film is used for the label, dust or the like adheres to the label, resulting in an imbalance between the label and the bottle body, which impairs the appearance.

<Means for Solving the Problems> The present invention has been conceived in order to solve the above problems, and uses the unstretched plastic film that has been subjected to antistatic treatment to the unstretched film used for the label. It is a solution to the problem.

 Hereinafter, the present invention will be described in more detail.

The film used as the base material for the in-mold label is an unstretched polypropylene film. The stretched film shrinks due to heat during molding of the plastic bottle, and wrinkles occur on the label after molding. As described above, it is necessary to use the unstretched film in order to follow the shrinkage of the bottle.

Next, the antistatic treatment applied to the unstretched polypropylene film will be described. Generally, for antistatic treatment, a surfactant is kneaded to form a film. As the surface active agent, a cationic surface active agent represented by primary amine salt, tertiary amine salt, quaternary ammonium compound, etc.,
Nonionic surfactants typified by ethylene glycols and sorbitan fatty acid esters are used in terms of antistatic effect and heat resistance.

The appropriate addition rate is usually 0.1% to 0.5%, preferably about 0.3%. The antistatic effect in this case is usually expressed by the surface resistivity value, which is 10 ¹⁰ Ω.
/ □ to 10 ¹³ Ω / □ is considered to be the range where dust is not attached.

During film formation, it is important to treat the film surface by corona discharge to improve the wetting characteristics of the surface so that printing and laminating can be easily performed.

Next, printing on the antistatic-treated unstretched polypropylene film (1) will be described.

The antistatic-treated unstretched polypropylene film (1)
Printing by means of gravure printing or the like is most effective for printing on, and even if a surfactant is kneaded, if urethane type ink is used, there is no problem with ink adhesion or the like.

As described above, the printed film is laminated with the adhesive resin (2) for adhering to the plastic bottle.

If the plastic bottle body is made of polyethylene, polyethylene resin is used, and if it is made of polypropylene, polypropylene resin is used.

There are two methods for laminating the adhesive resin (2), and dry laminating in which a film is attached via an adhesive,
Alternatively, an extrusion laminate that is stuck using an extruder is used.

In either case, a strong adhesive strength can be obtained by laminating a resin with an adhesive.

 The adhesive is preferably a urethane adhesive.

By the above method, an antistatic-treated unstretched polypropylene film (1) / printing / laminated film (3) having a layer structure of polyethylene resin (or polypropylene resin)
Can be created.

By punching the laminate film (3) described above into a label shape, it can be used as an in-mold label and can be integrally molded with a plastic bottle under normal in-mold molding conditions.

<Operation> Since the present invention is configured as described above and the label is subjected to the antistatic treatment, dust is not attached to the label as well as the bottle, and the appearance is not deteriorated.

<Examples> Examples of the present invention will be described below.

As an in-mold label substrate, 0.3% sorbitan fatty acid ester is added to polypropylene resin to form an unstretched polypropylene film (hereinafter abbreviated as CPP). Thickness 60
It was formed into a film.

The printing on the CPP film was performed by gravure printing using a urethane-based ink (Lamiter manufactured by Toyo Ink Co., Ltd.).

Adhesive layer with plastic bottle Laminated with resin is a urethane adhesive (Dainippon Ink &Chemicals' EPS75A
/ KW40), an adhesive was applied to the printed surface of the CPP film and dry lamination was performed.

In this example, since a high-density polyethylene resin (B5032A manufactured by Tonen Petrochemical Co., Ltd.) was used for the plastic bottle, a low-density polyethylene film (M14P film manufactured by TamaPoly Co., Ltd., thickness 40μ) was used as the adhesive resin. I was there.

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

The plastic bottle is a hollow molding bottle using a high-density polyethylene resin (B50302A antistatic agent kneading type manufactured by Tonen Petrochemical Co., Ltd.), and the above label was inserted into the mold at the time of molding and integrally molded.

As a result, a plastic bottle with a very high adhesive strength between the label and the bottle was obtained, and when the antistatic effect was measured as a surface specific resistance using an insulation resistance tester, it was 10 ¹² Ω.
It was / □, which was the same value as the surface resistivity of the plastic bottle body, and it was possible to obtain a plastic bottle in which dust and the like did not adhere even after long-term storage.

Comparative Example 1 In place of the antistatic-treated unstretched polypropylene film described in the examples, a general grade polypropylene film (3931 60μ thickness manufactured by Toray Gosei Co., Ltd.) was used.
The conditions of printing, adhesive resin, laminating method, plastic bottle, etc. were compared under the same conditions as in the examples.

As a result, the surface resistivity of the label was 10 ¹⁶ Ω / □ or more, and no dust adhered to the plastic bottle body after long-term storage, but the dust did not adhere to the label so much that it had no commercial value. there were.

<Effects of the Invention> When the plastic bottle and the label are integrally molded, the label is subjected to antistatic treatment, so it is possible to obtain a plastic bottle with a clean appearance that is free of dust on the plastic bottle body and the label. Became.

[Brief description of drawings]

FIG. 1 is a sectional view of a label according to the present invention. (1) …… Charging unstretched polypropylene film,
(2) …… Adhesive resin (3) …… Laminated film

Claims (1)

[Claims] 1. A labeled container obtained by integrally molding a label made of a plastic film simultaneously with molding of a plastic bottle, wherein the label comprises an unstretched plastic film subjected to antistatic treatment as a constituent element. Labeled container to do.