JPH0752935A - Transparent container - Google Patents

Abstract

PURPOSE:To provide a transparent container which has such an excellent releasing ability that the contents are kept free from the inner wall, even when the container is filled with strongly sticky and adherent contents and which is excellent in chemical resistance, physical strength and economy. CONSTITUTION:The structure of a transparent container 1 is made up of a polymethyl pentene layer 5, an adhesive polyolefin resin layer 6 and a shape retaining resin layer 7 in that order from the inside to the outside. The shape retaining resin layer 7 may preferably be of a gas-barrier resin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transparent container, and more particularly to a transparent container in which contents are prevented from adhering to the inner wall of the container.

[0002]

2. Description of the Related Art Conventionally, with the development of plastics, transparent containers made of PET (polyethylene terephthalate), PP (polypropylene), PE (polyethylene), PVC (polyvinyl chloride), PC (polycarbonate), etc. have been developed. Used in large quantities. These transparent containers are generally manufactured by blow molding.

In the case where a product having weak adhesiveness and adhesiveness such as an aqueous drink, food, seasoning, medicine, chemical, etc. is contained in the transparent container, the contents contained in the transparent container are transparent. Does not adhere to the inner wall of the container. For this reason,
When a consumer purchases a product, there is an advantage that the contents can be confirmed from the outside of the transparent container, and the remaining amount of the contents can be immediately known at the time of use. Therefore, many of the contents stored in the transparent container are pre-colored so that the state and increase / decrease can be discriminated at a glance.

On the other hand, when a content having particularly strong adhesiveness or adhesiveness is stored in the transparent container, the content remains attached to the inner wall of the transparent container during use, and the outside of the transparent container. However, there is a drawback that it is not possible to check the status and remaining amount of contents. For this reason, for example, when the contents are diluted and used, it is necessary to open the transparent container and check the remaining amount of the contents, which is troublesome.

Furthermore, it is difficult to use the contents stored in the transparent container to the end, and the transparent container is thrown away with the contents adhered to the inner wall, which is uneconomical. there were. Furthermore, when the transparent container contains chemicals such as pesticides which have particularly strong adhesiveness or adhesiveness, it is possible to discard the natural environment by discarding it while adhering it to the inner wall of the transparent container. There was a problem of causing it.

Therefore, in recent years, there has been studied a method of preventing the contents from adhering to the inner wall even when the contents having high adhesiveness or adhesion are contained in the transparent container.
As one of them, there is a method of reducing the surface activity of the packaging material by coating the surface of the packaging material that is in direct contact with the contents with a water-repellent material or a release material.

[0007]

However, since the transparent container is mainly formed by blow molding, a water-repellent material, a release material, or the like is preliminarily provided on the inner wall portion of the transparent container during blow molding. Cannot be coated. Therefore, the inner wall of the blow-molded transparent container is coated with a water-repellent material or a release material, but this is an extremely difficult work, and it is not possible to perform uniform coating on the inner wall of the transparent container. There was a problem.

An object of the present invention is to solve such a conventional problem, and even if the contents having strong adhesion and strong adhesion are accommodated, the contents adhere to the inner wall. It is an object of the present invention to provide a transparent container having excellent peelability, chemical resistance, physical strength and economy.

[0009]

In order to achieve this object, the present invention comprises a polymethylpentene layer, an adhesive polyolefin resin layer, and a shape-retaining resin layer in order from the inside to the outside. A characteristic transparent container is provided. Further, the present invention provides a transparent container in which the shape-retaining resin layer has a gas barrier property.

[0010]

The polymethylpentene forming the inner wall of the transparent container according to the present invention has no polar group in its molecular structure,
Does not absorb water and has very low surface activity. Therefore, even if the content having strong tackiness and strong adhesiveness temporarily adheres to the inner wall of the transparent container, the content is immediately repelled and separated from the inner wall of the transparent container. For this reason, since the contents do not adhere and remain on the inner wall of the transparent container, the transparency of the transparent container is not lowered and the contents are not wasted.

Since polymethylpentene is excellent in transparency and chemical resistance, it has physical properties suitable as an inner wall of a transparent container. Furthermore, since the shape-retaining resin layer is formed on the outside of the polymethylpentene layer (outside of the transparent container) via the adhesive polyolefin resin layer having excellent adhesiveness, the mechanical property as a container is improved. Strength is reinforced, and when the shape-retaining resin layer is a resin having gas barrier properties (hereinafter referred to as “gas barrier resin”), physical strength such as airtightness and impact resistance is added to mechanical strength. Will be reinforced.

Here, the adhesive polyolefin resin is excellent in transparency, heat resistance, chemical resistance, weather resistance, and the like, and firmly secures the polymethylpentene layer and the shape-retaining resin layer (gas barrier resin layer). To glue. Therefore, while the transparent container is in use, the polymethylpentene layer and the shape-retaining resin layer (gas barrier resin layer) do not peel off, and it has physical properties suitable as a resin (adhesive) constituting the transparent container. There is.

Further, in the transparent container according to the present invention, a polymethylpentene layer is formed inside a parison made of a shape-retaining resin layer containing a gas barrier resin layer via an adhesive polyolefin resin layer, and the parison is formed. It is formed by sandwiching with a desired mold, blowing air into the parison to expand it, and then cooling and solidifying. Therefore, the transparent container of the present application can be simply and economically manufactured without complicated coating technology.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment according to the present invention will be described with reference to the drawings. 1 is a sectional view of a transparent container according to an embodiment of the present invention, and FIG. 2 is a partially enlarged view of FIG.

As shown in FIGS. 1 and 2, the transparent container 1 according to the present invention comprises a polymethylpentene layer 5, an adhesive polyolefin resin layer 6 and a shape-retaining resin layer 7 in order from the inside to the outside. It has the following structure.

In this embodiment, the polymethylpentene layer 5 is a layer made of "TPX (trade name); manufactured by Mitsui Petrochemical Co., Ltd." and the adhesive polyolefin resin layer 6 is "Admer (trade name)". ); A layer made of "Mitsui Petrochemical Industry Co., Ltd." was used as the shape-retaining resin layer 7, and a layer made of "EVAL (trade name); .

The TPX is 4-methylpentene-1.
It is a polyolefin based on, has no polar groups in its molecular structure, does not absorb water, and has very small surface activity (surface tension (critical) = 24 dyne / cm). Therefore, even a substance having a strong adhesive property or a strong adhesive property has a property of being immediately repelled and peeled off. Further, since it has excellent transparency and chemical resistance, it is suitable as an inner wall of a transparent container.

The admer does not change with time, does not change at all when immersed in water, and has excellent durability against hot water, boiling water, and retort treatment. Moreover, the adhesiveness between TPX and EVAL is extremely high, and it is suitable as a resin constituting a transparent container.

The EVAL is obtained by copolymerizing polyvinyl alcohol, which has the lowest gas permeability among polymers, with ethylene which gives thermoplasticity while maintaining its crystallinity, and is excellent in impact resistance. Therefore, it is suitable as a resin constituting a transparent container.

The transparent container 1 is manufactured by the following method. First, the parison extruded from the extruder is sandwiched between molds having a desired shape. Here, the parison is formed to have a structure in which the outer side is formed of the shape-retaining resin layer 7 and the polymethylpentene layer 5 is formed inside the parison with the adhesive polyolefin resin layer 6 interposed therebetween.

Next, air is blown into the parison to expand it, and the shape of the mold is transferred. At this time, since the shape-retaining resin layer 7 and the polymethylpentene layer 5 are firmly adhered via the adhesive polyolefin resin layer 6,
It expands as a united party. Next, the expanded parison was cooled and solidified, and then the mold was removed to obtain a transparent container 1.

Thus, the transparent container 1 according to the present invention is
It can be manufactured by blow molding. Therefore, it is possible to easily and economically manufacture without performing a complicated process such as coating a water-repellent material or a release material on the inner wall of the transparent container which is formed in advance.

Next, the liquid releasability of the inner wall (polymethylpentene layer 5) of the transparent container 1 obtained in this example was investigated by the following method. First, in the transparent container 1, as a content 2, an agrochemical "Dokirin Flowable (trade name); manufactured by Nippon Pesticides Co., Ltd." having strong adhesiveness and strong adhesiveness is stored up to about 1/3. Next, after covering the transparent container 1 with the lid 3 and sealing the contents, the container 2 is laid down and rolled to evenly attach the contents 2 to the inner wall of the transparent container 1. Then, the transparent container 1 was made to stand upright, and the state where the content 2 was peeled from the inner wall of the transparent container 1 was visually observed.

As a result, the contents 2 attached to the inner wall of the transparent container 1 were immediately repelled and peeled off, and the transparency of the transparent container 1 was maintained. This is because the polymethylpentene layer 5 forming the inner wall of the transparent container 1 does not absorb water and has a very small surface activity.

Next, the same investigation was carried out using PET containers, PP containers, PE containers, PVC containers, and PC containers, and the contents remained on the inner walls of all these containers, Transparency is lost.

Further, the contents 2 were stored in the transparent container 1 for 30 days at 40 ° C.
There was no change in the amount or quality of the content 2, which proved that good storage could be performed.

Although "TPX" is used as the polymethylpentene layer 5 in this embodiment, the present invention is not limited to this.
Other products may be used as long as they contain polymethylpentene.

In this embodiment, "Admer" is used as the adhesive polyolefin resin layer 6, but the adhesive polyolefin resin layer 6 is not limited to this.
Other products may be used.

Further, since the shape-retaining resin layer 7 basically has only to have the mechanical strength required for a container, it may be made of PP, PE, PVC, PC or the like.
In this example, "EVAL" which is a gas barrier resin was used in order to enhance physical strength such as airtightness and impact resistance. However, other gas barrier resin may be used instead of EVAL, for example, desired resin such as PET, EVOH, PVDC, NY. When EVOH, PVDC or the like has a high gas barrier property but lacks in shape retention property, these resins and a resin having mechanical strength such as PP or PE are laminated via an adhesive agent to protect them. It may be the shape resin layer 7.

In this embodiment, the transparent container 1 is manufactured by blow molding in the sense of simplifying the manufacturing process and reducing the cost. However, the present invention is not limited to this, and the transparent container according to the present invention can be manufactured by another method. (For example, a multi-layer extrusion molding method, a tubular method) may be used.

Further, in the present embodiment, the pesticide was used for the examination of the liquid exfoliation property, but the contents 2 are not limited to this, and various contents such as other chemicals, highly viscous foods, waxes, etc. are contained. Can be saved.

In the present specification, the term "transparent" does not mean only 100% transparency, but also includes translucency and colored transparency. In other words, the contents include those with transparency such that the remaining amount can be confirmed from the outside.

[0033]

As described above, since the transparent container according to the present invention comprises the polymethylpentene layer, the adhesive polyolefin resin layer and the shape-retaining resin layer in order from the inside to the outside, it is strong. Even if the content having adhesiveness and strong adhesiveness temporarily adheres to the inner wall of the transparent container, the content can be immediately repelled and separated from the inner wall of the transparent container.

Further, by using a gas barrier resin as the shape-retaining resin layer, it is possible to reinforce physical strength such as airtightness and impact resistance as a container. further,
The polymethylpentene layer and the gas barrier resin layer are firmly bonded by the adhesive polyolefin resin layer. Furthermore, this transparent container can be formed by blow molding.

As a result of the above, the inner wall has excellent peelability so that the contents do not adhere, the state and the remaining amount of the contents can always be confirmed from the outside of the transparent container, and the chemical resistance, physical strength and economical efficiency are improved. An excellent transparent container can be provided.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a transparent container according to an embodiment of the present invention.

FIG. 2 is a partially enlarged view of FIG.

[Explanation of symbols]

 1 Transparent Container 2 Contents 3 Lid 5 Polymethylpentene Layer 6 Adhesive Polyolefin Resin Layer 7 Shape Retaining Resin Layer (Gas Barrier Resin Layer)

Claims (2)

[Claims] 1. A transparent container comprising a polymethylpentene layer, an adhesive polyolefin resin layer, and a shape-retaining resin layer in order from the inside to the outside. 2. The transparent container according to claim 1, wherein the shape-retaining resin layer has a gas barrier property.