JPS6169539A - Synthetic resin vessel for recovery - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to a three-layer, biaxially oriented synthetic resin container such as a bottle that can be recovered and used again after being covered with a cloth plate. .

(Prior art) Biaxially oriented synthetic resin containers molded using methods such as stretch blow molding are lightweight and have excellent transparency and impact resistance, and containers made of nolyethylene terephthalate in particular have good barrier properties. For this reason, its use as packaging bottles is expanding.

Containers such as biaxially oriented bottles are mainly single-layered, but attempts have been made to composite them with thermoplastic resins that have excellent performance in order to improve heat resistance and gas barrier properties. Containers with two or even three layer wall structures are being developed.

(Problems to be Solved by the Invention) Most synthetic resin containers for packaging are disposable and are not collected except in special cases.

For this reason, various problems arise when disposing of disposable containers, and for reasons such as resource conservation, it is considered that synthetic resin containers can be collected and reused in the same way as glass containers. There is.

Collected bottles and other containers (/i) are washed at high temperatures before being reused. Therefore, the synthetic resin used for the containers must be heat resistant and have excellent barrier properties. High surface hardness is required.

Furthermore, even if it is possible to completely clean the liquid, taking into account that it can be used as a container for other liquids (such as chemicals or gasoline) while being recovered, these liquids may still remain after cleaning due to osmosis. It is said that there should be no residual odor.

However, unlike glass, synthetic resins are easily permeated by gases and liquids, so from the standpoint of safety and hygiene, it is preferable to dispose of containers used for hazardous liquids and gases without reusing them. However, it is extremely difficult to completely inspect synthetic resin containers during sorting after collection, and unless this problem is resolved, synthetic resin containers cannot be collected and reused.

(Means for Solving Problems) Therefore, the object of the present invention is to provide a material that has excellent heat resistance and /SIJ carrier, has high surface hardness, and can be completely cleaned.
Harmful liquids other than those specified (chemical liquids, gasoline, etc.)
It is an object of the present invention to provide a new synthetic resin container for collection that can be easily recognized as having been used as a container.

As a result of various studies on collection containers made of synthetic resin, the present inventors have developed a three-layer composite of two different types of synthetic resins that meet several conditions for a collection container. , found that forming one container was most effective.

In addition, the synthetic 1 sealant that forms the container has excellent heat resistance and impact resistance, and has a hard surface that causes little damage to the surface even after repeated use.While it is non-toxic and hygienic, it has poor chemical resistance. By using a thermoplastic resin whose changes such as cracks and devitrification are easily visible from the outside, and by providing an intermediate layer of synthetic resin inside the resin that forms the container to compensate for the conditions that such resin lacks in the container. They discovered that many problems with collection containers could be solved.

Polycarbonate is well known as a resin with excellent heat resistance and impact resistance, and is also used for containers, but it is rarely used for packaging containers because of its poor barrier properties. Polycarbonate also has poor chemical resistance and is prone to cracks, devitrification, etc. due to contact, and depending on the substance, changes such as dissolution and decomposition may occur.

Although such changes in the resin are not desirable for containers used for collection that are used repeatedly, being able to detect these changes and dispose of the container is extremely beneficial in ensuring safety and health. , it is possible to prevent inhibition caused by harmful substances due to penetration.

Thermoplastic resins such as polyethylene terephthalate, ethylene-vinyl acetate copolymer, acrylonitrile, polyvinylidene chloride, polyamide, and polyethylene terephthalate co-polyamide are known as resins with transparency and barrier properties. If a resin is applied as an intermediate layer to supplement barrier properties inside the resin forming the container, a container for collection that fully satisfies the above-mentioned conditions can be obtained.

Therefore, the feature of the present invention is that at least the trunk wall and the bottom wall are composed of 31 parts including an inner and outer layer and an intermediate layer, and the inner and outer layers are made of a thermoplastic resin that has heat resistance but is easily changed by chemicals, and the intermediate layer is a thermoplastic resin with excellent barrier properties (formed with fat and used in synthetic resin containers for collection).

Further, the present invention will be specifically explained with reference to illustrated embodiments.

(Example) In the figure, 1 is a bottle body, and the body wall 2 and bottom wall 3 are molded into three layers in cross section. Two inner and outer layers forming this bottle body 4.4
The intermediate layer 5 is made of a stretch-blow moldable thermoplastic resin such as polycarbonate having excellent heat resistance and impact resistance, and the intermediate layer 5 is made of polyethylene terephthalate having excellent barrier properties.

The bottle body 1 can be molded very easily using known means. The molding begins with the inner and outer layers 4.
The resin of the intermediate layer 5 is placed in the center of the resin forming the resin 4, and both are injected concentrically into the cavity to form a bottomed TE ring with a three-layer cross section.

The thickness of the intermediate layer within this matrix varies depending on the intended use of the bottle molded therein, and the ratio of the inner and outer layers to the intermediate layer can be adjusted in any manner by adjusting the injection amount.

Is this the bottle body 1 above? The IJson can be easily molded by stretching it in the axial direction using conventional means and then expanding it with air pressure.

(Effect of the invention) As mentioned above, a three-layer container consisting of an inner and outer layer made of a thermoplastic resin that has heat resistance but poor chemical resistance, and an intermediate layer made of a thermoplastic resin with excellent barrier properties. It meets all the requirements for a recycled synthetic resin container, such as being able to withstand high-temperature cleaning, not losing its barrier properties, and determining whether to reuse the recycled container based on the presence or absence of changes in the inner and outer layers. It has the advantage of not causing a decrease in product value even in containers, completely eliminating the harmful effects of chemicals that penetrate before collection, and ensuring safety and hygiene at all times.

[Brief explanation of the drawing]

The drawing is a partial longitudinal sectional view of a synthetic resin container for recovery according to the present invention. l...Bottle body 2...Body wall 3
...Bottom wall 4 ...Inner and outer layers 5
...middle class

Claims (1)

[Claims] At least the trunk wall and bottom wall are composed of three layers: an inner and outer layer and an intermediate layer, and the inner and outer layers are made of a thermoplastic resin that has heat resistance but is easily changed by chemicals, and the intermediate layer has excellent barrier properties. A synthetic resin container for collection, characterized in that it is made of a thermoplastic resin.