JP2022012032A - Method for recycling synthetic resin-made container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for reusing a synthetic resin container, which can withstand a plurality of reuses of the synthetic resin container.
SOLUTION: This is a method of reusing a synthetic resin container in which a used synthetic resin container 1 is used again as a container, wherein the synthetic resin container 1 is a synthetic resin material containing a cycloolefin resin. A method for reusing a synthetic resin container, which is formed and whose inner surface 1a is coated with diamond-like carbon 10 and is characterized in that the used synthetic resin container 1 is alkaline-cleaned and used again as a container. ..
[Selection diagram] Fig. 1

Description

The present invention relates to a method for reusing a synthetic resin container in which a used synthetic resin container is used again as a container.

As containers for storing foods, beverages, cosmetics, detergents, etc. as contents, there are many synthetic resin containers such as polyethylene terephthalate resin (PET) bottle containers and polypropylene resin (PP) injection cup containers. It is used.

Conventionally, as a container made of synthetic resin, polyethylene terephthalate resin, polypropylene resin, etc. have been used in order to enhance the barrier property against oxygen and the like, and to reduce the adsorptivity of fragrance and odor so that the container can be used again after use. A technique is known in which a diamond-like carbon (DLC) is coated on the inner surface of a synthetic resin container made of the synthetic resin material (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2007-07734

When a glass bottle or a metal can is used again as a container after use, it is common to perform alkaline cleaning of the used container with an alkaline cleaning solution. It is considered that the contents of the synthetic resin container can be effectively washed by alkaline cleaning when the container is used again after use.

However, in a container made of a synthetic resin made of polyethylene terephthalate resin, such as the above-mentioned conventional container made of synthetic resin, in which the inner surface is coated with diamond-like carbon, diamond-like carbon becomes a synthetic resin when alkaline cleaning is performed. There is a problem that peeling easily occurs from the inner surface of the manufacturing container and there is a possibility that it cannot withstand multiple reuses.

An object of the present invention is to solve such a problem, and an object thereof is a synthetic resin container capable of making a synthetic resin container able to withstand a plurality of reuses. Is to provide a reuse method for.

The method for reusing a synthetic resin container of the present invention is a method for reusing a synthetic resin container in which a used synthetic resin container is reused as a container, wherein the synthetic resin container is a cycloolefin resin. It is characterized in that a container made of a synthetic resin material containing the above-mentioned material and having a diamond-like carbon coated on the inner surface thereof is used, and the used synthetic resin container is alkaline-cleaned and used again as a container.

In the method for reusing the synthetic resin container of the present invention, it is preferable to use the synthetic resin container formed of a cycloolefin polymer resin and coated with diamond-like carbon on the inner surface in the above configuration.

In the method for reusing the synthetic resin container of the present invention, it is preferable to use the synthetic resin container formed of the cycloolefin copolymer resin and coated with diamond-like carbon on the inner surface in the above configuration.

In the method for reusing a synthetic resin container of the present invention, it is preferable that the synthetic resin container is a bottle container formed by blow molding in the above configuration.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a method for reusing a synthetic resin container, which can make the synthetic resin container able to withstand a plurality of reuses.

It is a partially cutaway front view of the synthetic resin container used in the method of reusing the synthetic resin container which is one Embodiment of this invention.

Hereinafter, the present invention will be described in more detail with reference to the drawings.

The synthetic resin container 1 shown in FIG. 1 is used in the method for reusing a synthetic resin container according to an embodiment of the present invention. That is, the synthetic resin container 1 is a reusable container or a returnable container that can be reused as a container after use.

The synthetic resin container 1 is a blow-molded product formed by biaxially stretch-blow-molding a synthetic resin preform formed into a bottomed tubular shape by injection molding, and has a cylindrical mouth portion 2 and a mouth. A bottle container having an enlarged diameter shoulder portion 3 integrally connected to the lower end of the portion 2, a cylindrical body portion 4 integrally connected to the lower end of the shoulder portion 3, and a bottom portion 5 for closing the lower end of the body portion 4. It has become.

A male screw 6 is integrally provided on the outer peripheral surface of the mouth portion 2, and a cap (not shown) is replaced with the male screw 6 and screw-coupled so that the mouth portion 2 can be closed with the cap. In addition, a protrusion for undercut engagement may be provided on the outer peripheral surface of the mouth portion 2 instead of the male screw 6, and the cap may be attached to the mouth portion 2 by tapping.

The synthetic resin container 1 is made of a synthetic resin material containing a cycloolefin resin, and its inner surface 1a is coated with diamond-like carbon (DLC) 10. The synthetic resin material containing the cycloolefin resin may be composed of only the cycloolefin resin, and the cycloolefin resin contains other synthetic resin materials such as polypropylene and polyethylene, additives, and the like. It may be a synthetic resin material. Further, in the synthetic resin container 1, if the inner surface 1a coated with the diamond-like carbon 10 is made of a synthetic resin material containing a cycloolefin resin, for example, each contains a cycloolefin resin. It may be configured to have a layer formed of another synthetic resin material, a recycled material, or the like between the outer layer and the inner layer formed of the synthetic resin material, or a synthetic resin containing a cycloolefin resin. A layer formed of another synthetic resin material, a recycled material, or the like may be provided on the outside of the layer formed of the material. In the present embodiment, the synthetic resin container 1 is formed of a cycloolefin polymer resin (COP resin), which is a kind of engineering plastic, and the entire inner surface 1a is coated with diamond-like carbon 10. There is. Examples of the cycloolefin polymer resin include "ZEONOR (registered trademark) 1020R" (glass transition temperature 102 ° C.) manufactured by Zeon Corporation and "Zeonex (registered trademark) 5000" (glass transition temperature 68 ° C.) manufactured by Zeon Corporation. Can be used.

The diamond-like carbon 10 is formed in a layer on the inner surface 1a of the synthetic resin container 1 as an amorphous hard film (amorphous carbon film) made of a hydrocarbon or an allotrope of carbon, for example, by a vapor deposition method. ..

The synthetic resin container 1 may be formed of a cycloolefin copolymer resin (COC) instead of the cycloolefin polymer resin, and the inner surface 1a may be entirely coated with diamond-like carbon 10. As the cycloolefin copolymer resin, for example, "TOPAS (registered trademark) 8007F-04" (glass transition temperature 78 ° C.) manufactured by Polyplastics Co., Ltd. can be used.

The synthetic resin container 1 having the above configuration is filled with contents such as foods, beverages, cosmetics, and detergents, and the mouth 2 is closed with a cap to store the contents. Can be used as. The synthetic resin container 1 as a container containing the contents is distributed in the market, and the contents are poured out and used by the consumer at a consumption site such as a home.

Since the synthetic resin container 1 having the above structure has a diamond-like carbon 10 coated on its inner surface 1a, the synthetic resin container 1 has a barrier property against oxygen and the like to suppress oxidation of the contents. At the same time, it is possible to suppress the aroma and odor of the contents from being adsorbed on the synthetic resin container 1.

The method for reusing the synthetic resin container according to the present embodiment is a method for reusing the synthetic resin container in which the used synthetic resin container 1 is used again as the container, and the synthetic resin container 1 is described above. As shown in the above, using a synthetic resin material containing a cycloolefin resin and having a diamond-like carbon 10 coated on the inner surface, the used synthetic resin container 1 is alkaline-cleaned and used again as a container. It is characterized by doing.

That is, in the method of reusing the synthetic resin container according to the present embodiment, the synthetic resin container 1 having the above configuration is used as a container for storing the contents, and then alkaline cleaning is performed to re-use the contents. It is intended to be used as a container for storing.

In the alkaline cleaning, the synthetic resin container 1 is cleaned with an alkaline cleaning solution such as an aqueous solution of sodium hydroxide having a concentration of 4%. By alkaline cleaning the used synthetic resin container 1, the contents adhering to the inner surface 1a of the synthetic resin container 1 are effectively removed, and the synthetic resin container 1 can be reused as a container. Can be washed. Before and after the alkaline cleaning, preliminary cleaning may be performed using warm water, another cleaning solution, or the like.

The synthetic resin container 1 washed by alkaline washing can be reused as a container for storing the contents by refilling the contents and closing the mouth portion 2 with a cap.

At this time, since the inner surface 1a of the synthetic resin container 1 is coated with diamond-like carbon 10 to suppress the adsorption of the odor and odor of the contents stored last time, the synthetic resin container 1 is reused. When doing so, it is possible to prevent the aroma and odor of the contents stored last time from adversely affecting reuse.

In the method for reusing the synthetic resin container of the present embodiment, the synthetic resin container 1 is made of a synthetic resin material containing a cycloolefin resin, so that the synthetic resin container 1 is used. The diamond-like carbon 10 coated on the inner surface 1a can be prevented from peeling off from the inner surface 1a during alkaline cleaning, so that the synthetic resin container 1 can withstand a plurality of reuses.

Here, in the experiment conducted by the inventor, "ZEONOR (registered trademark) 1020R" (glass transition temperature 102 ° C.) manufactured by Nippon Zeon Co., Ltd. and "Zeonex (registered trademark) 5000" (glass transition temperature 68) manufactured by Nippon Zeon Co., Ltd. ℃), a synthetic resin container with diamond-like carbon coated on the inner surface of a bottle container or cup container formed using "TOPAS (registered trademark) 8007F-04" (glass transition temperature 78 ° C) manufactured by Polyplastics. It was confirmed that the diamond-like carbon did not peel off even when immersed in an aqueous solution of sodium hydroxide having a concentration of 4% for 10 minutes, and was suitable for reuse by alkaline washing.

On the other hand, polyethylene terephthalate resin (PET), polyethylene naphthalate resin (PEN), polylactic acid resin (PLA), modified polyethylene terephthalate resin (PETG), polyhydroxyalkanoate resin (PHA), polybutylene succinate resin (PBS). ), The inner surface of the bottle container or cup container is coated with diamond-like carbon, and when the synthetic resin container is immersed in a sodium hydroxide aqueous solution having a concentration of 4% for 10 minutes, the diamond-like carbon is peeled off. It was confirmed that it is not suitable for reuse by alkaline cleaning.

As described above, in the method for reusing the synthetic resin container of the present embodiment, the synthetic resin container 1 is formed of a synthetic resin material containing a cycloolefin resin, and the inner surface 1a is coated with diamond-like carbon 10. Therefore, even if the synthetic resin container 1 after use is alkaline-cleaned, the diamond-like carbon 10 is prevented from peeling off, and the synthetic resin container 1 is effectively cleaned by alkaline cleaning. It can be made to be able to withstand multiple reuses while being configured to be washable.

Further, by using a container made of a cycloolefin polymer resin or a cycloolefin copolymer resin as the synthetic resin container 1, the above effect can be obtained more reliably.

Further, when the synthetic resin container 1 is a bottle container formed by blow molding, the inside of the bottle-shaped synthetic resin container 1 is effectively washed by alkaline cleaning and reused a plurality of times. Can withstand.

It goes without saying that the present invention is not limited to the above-described embodiment and can be variously modified without departing from the gist thereof.

For example, in the above embodiment, the synthetic resin container 1 is used as a bottle container, but the present invention is not limited to this, and the container may be formed of a cycloolefin resin and the inner surface 1a thereof may be coated with diamond-like carbon 10. For example, a container having another shape or use, such as a cup container formed into a cup shape by injection molding, may be used.

Further, as the cycloolefin-based resin constituting the synthetic resin container 1, various materials or grades can be used.

Further, the synthetic resin container 1 is not limited to the one formed by biaxial stretching blow molding of the preform, but may be formed by other molding methods such as extrusion blow molding and injection molding.

1 Synthetic resin container 1a Inner surface 2 Mouth 3 Shoulder 4 Body 5 Bottom 6 Male screw 10 Diamond-like carbon

Claims (4)

It is a method of reusing a synthetic resin container in which a used synthetic resin container is used again as a container.
As the synthetic resin container, a container made of a synthetic resin material containing a cycloolefin resin and having a diamond-like carbon coated on the inner surface is used.
A method for reusing a synthetic resin container, which comprises alkaline-cleaning the used synthetic resin container and using it again as a container. The method for reusing a synthetic resin container according to claim 1, wherein the synthetic resin container is formed of a cycloolefin polymer resin and has a diamond-like carbon coated on the inner surface. The method for reusing a synthetic resin container according to claim 1, wherein the synthetic resin container is formed of a cycloolefin copolymer resin and has a diamond-like carbon coated on the inner surface. The method for reusing a synthetic resin container according to any one of claims 1 to 3, wherein the synthetic resin container is a bottle container formed by blow molding.

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